“The object of the artist is the creation of the beautiful. What the beautiful is, is another question.”
~ James Joyce
The true beauty of Jensen Knives comes from their mixture of form and function, merged with the finest exotic array of natural material combinations sourced specifically for these unique creations. These rare specimens come from every corner of the world and even beyond; from the most remote geological mines, to deep beneath the sea; from the hostile arctic circle, to ancient fossil beds, and even meteorite from outer space.
John’s unique gift in being able to seamlessly combine both exquisite, natural materials (many of which date to 30,000 years old or more), along with the finest in state-of-the-art, man-made materials and metal alloys, culminates in a fine balance of the most intricate combinations of patterns, colors, and textures.
DAMASCUS (“PATTERN-WELDED STEEL”)
Damascus steel is now coveted for the intricate beauty of its patterns, but the origin of this steel was almost certainly a matter of practical concern. Early methods of refining and alloying steel lacked the high temperatures necessary to reduce iron silicate completely. The result was a coarse-grained material that was unsatisfactory for implements requiring a fine edge and a polished surface. As a common practice, blacksmiths would hammer out material to refine its crystalline structure. Because the hammering thinned the stock, it was necessary to fold the steel over periodically to create enough mass to repeat the process. As the steel was continually reheated, it picked up carbon from the fire, creating a carbon “skin”. When it was folded and forge-welded, the “skin” would become a layer of stripe within the steel. After dozens of foldings, the steel took on the beautiful patterns we recognize today.
It appears that many cultures independently developed this layered steel all many centuries ago. Examples have been found in excavations in Scandinavia, Poland, Britain, China, Japan, and around the Mediterranean. Artifacts dated from Europe, dated as early as 200BC, show the smith’s obvious intent to control the pattern visible on the surface of the finished item. The pattern is both a guarantee that the “iron” has been worked enough to make it better, and an aesthetic expression by the maker. The steel was popularized in Europe when it was brought back from the crusades. At the time of the crusades, the term “Damascus steel” begins to appear in European languages to describe the swords encountered in the middle east. Persian swords, knives, spears, etc. Had a pattern visible on the surface, but the method of production differed from forge welding. The Persian swords were made by carefully forging a “cake” of “wootz”. Wootz is a type of steel made by melting the metal in a small crucible and letting it solidify slowly enough to form segregated areas of high and low carbon content. Thereafter, the term “Damascus steel” was used universally to describe steel with a visible pattern, whether it was made from wootz or by forge welding different steels together. It was then linked with the city of its “source” and acquired the name “Damascus”. Because it was widely produced outside that region, the term is unfortunately misleading.
The term is even less appropriate now because the process as popularly done does not involve the repeated folding of a single material. In order to create bold and dramatic patterns, it is common now to start with two or more distinct materials that will make a clear color difference. These are stacked in alternate layers and forge welded and fused together. Because the point of this process is to create a pattern, the material is properly called pattern-welded steel. The word Damascus is so entrenched, however that it is unlikely to be replaced by the technically more accurate term.
In a polished blade of layered steel, the pattern is almost impossible to see. Historically the effects of corrosion, through the atmosphere and handling, wore away the component materials at different rates. This revealed the pattern. It is common practice now to use acid and/or chemical colorants to attack the steel. This hastens the action and gives the knife-smith some control over the look of the finished blade.
Toward the middle of the second millennium the popularity of knives of pattern-welded steel for knives and swords had fallen to near zero. By this time, however, firearms were becoming popular. Once again, pattern-welded steel (now called Damascus) in gun barrels and gun parts became fashionable. The industrial revolution, and inexpensive high quality homogeneous steel, brought a close to the use of Damascus steel for gun barrels. By the end of the first world war, the popularity of Damascus again had declined.
It was in the united states, in the early 1970’s, that the third wave of Damascus popularity was revived along with a general flowering of contemporary crafts. Knife maker Bill Moran exhibited hand-made, pattern-welded knives at the 1973 “knifemakers guild” show at Kansas City, Missouri. These knives caught the attention of journalists and over the next few years, a profusion of articles about knife making, accompanied by photos of the knives, appeared in popular hunting, fishing, and outdoor magazines.
This same year, Daryl Meier started his exploration of this material after seeing a demonstration by Ivan Bailey, who had recently brought back the process from “art-smith” school in Germany. From there, Daryl went on to head the “Damascus Research Team” at the university of Carbondale, Ill. Meier was the first in the knife-making community to provide the steel to others. He has taught and influenced, in one way or another, most of today’s prominent Damascus makers. Daryl Meier is truly the grandfather of modern Damascus.
Again, the public became aware of what could be done with pattern-welded steel, and its potential. Their interest encouraged the rapid growth that has occurred. In 1974 three makers of pattern-welded steel knives exhibited at the Kansas City “Knife Makers Guild” show. Today, there are hundreds, if not thousands of knife makers using pattern-welded steel. Additionally, there are several small factories, and one large factory producing pattern welded steel for knives, swords, jewelry, gun parts, and even golf clubs.
Modern makers have duplicated almost all the patterns found in old artifacts. Not surprisingly, developing new patterns that never before existed has been a challenge. Since about 1990, patterns that have never before existed have been developed. Blade-smiths are taking advantage of new combinations of steel that include all stainless steel mixes, and some by powder metallurgy.
The basic technique for creating pattern welded steel is to make a stack of alternating pieces of two or more different steels. The difference between the components has a lot to do with the intensity of the pattern. Very unlike materials will create the most obvious distinction between the layers. Very unlike materials are also the hardest to fuse together. In selecting steels, the smith seeks a balance of the layers and a showy pattern when the blade is finished. The stack is then forge-welded and drawn out to be folded or cut and re-stacked, then forge-welded again. When sufficient layers have been achieved, the bar is forged, bent, twisted, or manipulated in some way, to create the desired pattern. It is then forged, or ground to final shape. The last step in finishing the piece is usually an etching of the surface to enhance the visibility of the pattern. The possibilities of what can be achieved regarding patterns is endless, and is only limited by ones’ imagination.
FOSSIL IVORY
Fossil ivory is found all over the world and includes Wooly Mammoth, Mastodon, and Walrus. Unlike most other prehistoric animals, their remains are often not literally fossilized – that is, turned into stone – but rather are preserved in their organic state, and is actually best described as ancient ivory. This is due in part to the frozen climate of their habitats, and also to their massive size. Instead of decaying or undergoing petrification, ivory from animals that died hundreds, or even thousands of years ago often remains much as it was, though sometimes taking on coloration from surrounding minerals, this can result in intense coloration and patterns. No animals were harmed or killed due to the acquisition of this material.
Fossil walrus ivories are primarily found on St. Lawrence Island, Alaska, it weathers out of the stream beds and along the beaches. A small amount is found from the Alaskan herd, and some along the Alaskan coast. The majority of it is excavated by Eskimos from their ancestral village sites, as a source of income. Walrus ivory is usually between 500 and 3000 years old, and generally doesn’t exceed 10,000 years old. Walrus tusks were often modified for use as ice axes, by flattening a section to facilitate the attachment of a handle, then they were lost or discarded. Other examples of use include sled runners, fire starters, harpoon or spear tips, as well as decorative items such as figurines and jewelry. These artifacts, if not archaeologically significant, are often used as raw material. Ancient walrus ivory does not differ from modern ivory except in coloration. There is a hard enamel layer on the outside of the tusk, usually no more than 1/2 cm thick, then there is a layer of dentin, which does not display much of any grain. The core of the tusk is distinctively different, having a characteristic grain pattern resembling tightly compressed spheroids. Coloration is primarily from minerals in the soil… Copper for the blues and greens, manganese and iron for the browns and oranges, gold for the rare reds….and seaweed in some cases.
Mammoth and mastodon ivory is found in the Alaskan arctic, Canadian Yukon and Siberia for the majority of the material, though there is material also found in more places in the world than not, from china to South America, all over the U.S. and Mexico. Fossil mammoth ivory can come in the form of whole perfect tusks, which are often mounted as specimens. The tusks can also delaminate into long curved sheets of fairly thin material arranged concentrically around the core. Proboscidian ivory may be recognized by the grain pattern visible in a cross section, which displays a double spiral pattern, a series of clockwise spirals crossing others running counter-clockwise. If one thinks of the crossings of these spirals as being the points of a star shape, ivory with acute angles at the points of the star is from modern elephants, mammoth and mastodon ivory shows obtuse angles instead. Except for an isolated herd of pygmy mammoth that died out about 3000 years ago on a Siberian island, it is all pre ice-age; 10,000 years old to possibly a million or so years old. Coloration occurs from the same above named minerals, and anything else that could leech into the ivory during countless cycles of thaw and freezing. The same process causes the minerals to leech into the walrus ivory.
Most of the mammoth ivory is found as a consequence of gold mining, mostly in Canada and Alaska. In Siberia it is mined for its own sake, often found in deposits after violent winter storms have revealed a portion of the material sticking up from the perma-frost near ancient lake beds, and it’s further excavated from there, where it has been a resource for centuries. The Russians have been industrious in developing a world market for their ivories…. The U.S, and Canada lag far behind.
FOSSIL MAMMOTH TOOTH
The teeth of mammoths are quite distinctive, they consist of a series of compressed plates composed of enamel surrounding a dentine core. These tooth structures are held together in a matrix of cementum. These cemented plates make a very tall, strong, and wear-resistant tooth.
After a tooth erupts from the gum cavity, the mammoth uses it in grinding coarse vegetation like grass. Grass is a very hard material to eat: it has small pieces of silica (a glass-like substance) in its leaves. These pieces of silica act like sandpaper grit and would wear away a less resistant tooth very quickly. This use causes the tooth to develop a flat top with low enamel ridges where the plates have been worn. Teeth erupted from the back of the jaw and slowly moved forward as it wore to be replaced by another tooth from behind.
The unique structure of the teeth create beautiful internal patterns and surface qualities, and change depending on how the tooth is cut. The different layers make working the material difficult, but benefits include the ability to have book-matched pairs, and larger sizes and thicknesses than many other materials.
GEMSTONES
A | B | C | D | E | F | G | H | I | J | K | L | M | N | O | P | Q | R | S | T | U | V | W | X | Y | Z
Agate: mohs hardness: 6.5-7
Agate is a form of chalcedony that occurs in nodular masses in rocks such as volcanic lavas. Inside, agate reveals an amazing variety of colors and patterns and a distinct banding which distinguishes it from other types of chalcedony.
Amber: mohs hardness: 2-3
Amber is an organic gem formed from the hardened, fossilized sap or resin of ancient pine trees. Amber often contains bubbles and other small inclusions such as small plant or animal fossils. Though its transparency and color varies, the most common colors are orange, yellow, and brown. It also occurs in green.
Amethyst: mohs hardness: 7
Amethyst is the best known and most valuable form of quartz. Its color is caused by iron or manganese compound impurities in the mineral. The best quality comes from Russia and brazil. Amethyst was supposed to have many useful powers in the 15th century, but its traditional virtue was its ability to cure drunkenness.
Aquamarine: mohs hardness: 7.5-8. March birthstone
A variety of beryl meaning “sea water”, which accurately describes its color. It has a range from pale green to blue, caused by varying amounts of different forms of iron. It is relatively common, with sources in many countries, brazil being the main.
Beryl: mohs hardness: 7.5-8
A transparent pale green, blue, or yellow mineral consisting of a silicate of beryllium and aluminum, sometimes used as a gemstone.
Carnelian: mohs hardness: 6.5
Carnelian is a type of chalcedony that is a translucent reddish-orange. Its color comes from its iron oxide content and stones may present a uniform color or be faintly banded.
Chalcedony: mohs hardness: 7
A variety of quartz that’s composed of microcrystalline quartz crystals and hydrated silica (opal). Agate, jasper, carnelian and chrysoprase are all varieties.
Citrine: mohs hardness: 7
Slow heating turns amethyst into citrine, a yellow variety of quartz. It is often mistakenly called topaz. Citrine rarely occurs in natural deposits and is a valuable collector’s item.
Diamond: mohs hardness: 10. April birthstone
The word diamond is derived from the Greek word ‘adamas’, meaning ‘unconquerable’, given to the stone because of its supreme hardness. Diamond is made of pure carbon, each carbon atom is strongly bonded to four others to form a rigid, compact, immensely strong crystal structure. It is this which makes it the hardest of all minerals. Diamonds form in the earth’s mantle in conditions of extreme heat and pressure. At depths of about 93 miles they develop a compact atomic structure that gives them their hardness. Volcanic eruptions bring the diamond to the earth’s surface. Some stones may be as much as three billion years old. Diamonds were first discovered over 2000 years ago and came mainly from river gravel in India. In 1725 they were found in brazil, which remained the major source until production in south Africa became significant in 1870. Today, about 20 countries produce diamonds. The top producer is Australia, which supplies a quarter of the worlds’ needs, mainly for industrial purposes. Diamonds are used in a vast number of jobs mainly because they are so hard. They are used in sawing, drilling, grinding and polishing-from quarrying stone to performing delicate eye surgery, and come in a vast array of sizes , shapes and strengths. The most familiar consideration of the cut gemstone are what we know as the four “C”s; color, cut clarity, and carat. The most traditional cut is the “brilliant” with 57 facets. Diamonds are also available in every color, including black.
Emerald: mohs hardness: 7.5-8. May birthstone
Emerald belongs to the beryl family and gets its green color from traces of chromium and vanadium. The finest examples of this precious stone come from Columbia, where they have been mined for many centuries. Many are mine and exported illegally and there are often robberies and murders connected to this stone.
Fire opal: mohs hardness: 5-6.5
These opals tend to have one body color and do not usually contain the flashes of light and color typical of other opals, it is the only natural opal that is normally faceted. Generally found as an intense red-orange color, hence the name.
Garnet: mohs hardness: 7-7.5. January birthstone
Garnet is the name of a group of chemically related, silica based minerals that includes almandine, pyrope, spessartine, grossular, and andradite. They can all be used as gemstones, the almandine-pyrope group being the most widely used. Because of the different chemical compositions, garnet occurs in most colors, except blue. Sources of gem-quality material include Czechoslovakia, South Africa, USA, Australia, brazil and Sri Lanka. The name garnet may have come from the Latin word used for pomegranate, ‘granatum.’ you can easily see the similarity of the colors of the glossy gemstone and the seeds of the fruit.
Hematite: mohs hardness: 6-6.5
Hematite is iron oxide, a common iron ore found in igneous rock. Kidney-shaped lumps and shiny black crystals are both common forms of hematite. Hematite gemstones are opaque with iridescent surfaces.
Iolite: mohs hardness: 7-7.5
Iolite is the gem name for cordierite, a silicate of aluminum and magnesium. Iolite is sometimes called dichroite, alluding to its dichroic properties; it shows two or more colors according to the direction in which it is viewed through transmitted light. Most iolite is found in gravel beds in the form of water-worn pebbles.
Jade: mohs hardness: 6-7
Jade is tougher than steel, but soft enough to be suitable for carving. The Spanish conquerors of Mexico believed that the Indian’s green stones would cure kidney ailments. They called them kidney stones or ‘piedras de hijades’ and from this the word jade was derived. In Europe, the name was then given to material of the same color and hardness which was imported from china. It was first used as tools and weapons. Later it was made into jewelry and ornaments. In 1863, the French scientist Damour showed that two different minerals shared the name jade. “jadeite” is composed of interlocking, granular pyroxene crystals. Nephrite is an interlocking aggregate of fibrous amphisole crystals. Colors range from white, cream, grey, soft to medium mint green, spinach green, dark olive green to near black.
Lapis lazuli: mohs hardness: 5.5
Lapis lazuli is not a single mineral but a rock consisting of blue lazurite with variable amounts of calcite and pyrite. The name is derived from the Persian word ‘lazhward’, meaning blue. The blue color is caused by sulfur which is an essential part of its composition. In medieval times lapis lazuli was crushed and purified to make the paint pigment ultramarine. Primarily mined in Afghanistan, other sources include the Soviet Union and Chile.
Malachite: mohs hardness: 3.5-4
Copper minerals near the earth’s surface alter when exposed to water and cool temperatures. Malachite often forms in these conditions. It is often found as kidney-shaped masses surrounded by bands of color. It always has a green color which varies only in intensity. Malachite is widely used as a decorative stone. It is also a secondary ore of copper.
Moonstone: mohs hardness: 6-6.5
The most familiar gem variety of feldspar minerals. The white or blue iridescent sheen is caused by layers of tiny crystals of albite within orthoclase and is called ‘adularescence”. Some varieties may be steely gray, orange pink, yellow, or pale green. The gray stones particularly may show good cat’s eyes.
Opal: mohs hardness: 5-6.5. October birthstone
Opal is a relatively soft semi-transparent solidified mineral composed of silicon and water. The popularity of opal has risen and fallen over the centuries. The ancient romans used it as a symbol of power but since then, at different times, it has been considered to be unlucky. The Aztecs mined opal over 500 years ago in central America. Australia is the top producer of both black and white opals; they were first discovered there in the 1870’s. Opal is one of the few non crystalline gems. It has a tendency to crack and chip, especially under extreme temperature changes or after a hard knock. The exciting flashes of color shown by precious opal are best displayed in cabochons.
Peridot: mohs hardness 6.5-7. August birthstone
Peridot is a French word and may derive from the Arabic ‘faridat’, meaning a gem. It is the gem variety of a group of minerals that are found in igneous rocks called olivine, a magnesium and iron silicate that is common in volcanic rocks. This group only forms in molten rock beneath the earth’s surface. Peridot is yellowish to olive green with an oily luster. The finest peridot specimens come from the island of zebirget in the red sea.
Quartz: mohs hardness: 7
Quartz is a silicon dioxide. It occurs as individual crystals and fine-grained masses in a large variety of forms, patterns, and colors. It is widely distributed as veins and is associated with major mineral deposits. It is one of the chief materials in granite and is also the main component of sand and sandstone. As quartzite and sandstone, it is used extensively for building and in the manufacture of glass and ceramics. One of the most interesting properties of quartz crystals is piezoelectricity, this is an electric charge produced by applying pressure to them, which gives quartz many uses and contributes to its value.
Ruby: mohs hardness: 9. July birthstone
Ruby, a variety of corundum, is one of the world’s most valuable gemstones. A ruby’s color is due to a trace of chromic oxide; the amount of this substance determines the depth of color. Because of their hardness and durability, rubies are an excellent choice for all types of jewelry. Star rubies asterisk is caused by needle-like inclusion of rutile.
Sapphire: mohs hardness: 9. September birthstone
Sapphire is a member of the corundum family. Blue sapphire takes its color from titanium and iron oxides; the depth of color depends on the amount of oxides present. Star sapphires are available in blue and black. White sapphires are sometimes diamond substitutes. Some of the finest sapphires occur in river gravel in Kashmir. They originally formed in rocks beneath the Himalayas. Other colors are yellow and pink.
Tanzanite: mohs hardness: 6-7
A purplish blue gem variety of the mineral zoisite. It was found in northern Tanzania in 1967 and is remarkable for its displays of rich blue, magenta, and yellowish grey. Many crystals are greenish grey and are heat treated to the more attractive blue. It is trichroic- it often exhibits different colors when seen from different directions.
Tiger’s eye: mohs hardness: 7
Tiger’s eye is a variety of quartz with fine, similarly oriented fibrous inclusions. Tiger’s eye first develops with tiny fibers of silky blue asbestos. These were then dissolved by solutions which deposited quartz and iron oxides in their place. This gives rise to the light reflection know as chatoyancy (changeable lustre) or “cat’s-eye.”
Topaz: mohs hardness: 8. November birthstone
A common misconception is that all topaz is yellow; pure topaz is colorless, but the gem actually occurs in a broad range of colors including yellow, brown, pink, red, blue and green. Blue topaz is demarcated from lightest to darkest by: American (or maxi), Swiss and London.
Tourmaline: mohs hardness: 7-7.5
Tourmaline comprises ten mineral varieties. The range of color seen in tourmaline is the greatest of any mineral. Even a single crystal can have several colors. Tourmaline is a mineral with a complex chemistry. It crystallizes as prisms with flat or wedge-shaped terminations. Every crystal has a different structure at each end, sometimes indicated by different colors. This gives tourmaline an unusual electrical property. If a crystal is gently warmed, one end becomes positively charged and the other negatively charged. Tourmaline is a pleochroic mineral. This means that it looks a different color when viewed from different angles. It forms in igneous and metamorphic regions. It also forms in mineral veins. Tourmaline can grow with other minerals such as beryl, quartz, and feldspar.
SHELL
Pearls have intrigued humans for thousands of years. These mysterious and beautiful objects have a rich cultural history, they have funded business and industry, initiated conquest and exploration, adorned religious and secular art, and have been associated with royalty and celebrity.
Mollusks constitute one of the most diverse animal phyla on earth, with over 100,000 living species. They build the shells in which they live in, as well as pearls themselves. The shell and the pearls are made from the same material…
Aragonite (“ah-rag-uh-nite”) and conchiolin (“kon-kee-uh-lin”) are the two materials the animal uses to build its shell. The mineral aragonite is arranged in sheets of flat six-sided crystals. Between each sheet, the mollusk secretes a very thin layer of the membrane-forming conchiolin. This composite material is called nacre (“nay-ker”) or mother-of-pearl. The crystalline structure of nacre reflects light in a unique way. One of the most distinctive features of nacre is the way it seems to glow from within. This property, known as “luster,” gives pearl its unusual beauty. Luster results from the reflection of light rays not only off the surface, but also off the inner layers of nacre. The multiple layers of nacre also gives rise to the iridescence and orientation. The layers of nacre act like tiny prisms, refracting light so that it appears as all the colors of the rainbow. Pearls occur naturally in a spectacular array of colors, ranging from white to gold, purple and black. A pearls color depends on both the species of mollusk that produced the pearl and the environment in which the animal lived. In general, crystals of aragonite are white or colorless. The natural color of pearl is mostly due to conchiolin, which contains organic pigments.
Mother-of-pearl comes from the south pacific (Indonesia, Philippines, Tahiti, Australia, etc…) Much of the material comes from farmed shells, but a large percentage of mother of pearl does in fact grow naturally in its natural habitat, and until the 20th century, divers in these regions spent most of their time hunting for mother-of-pearl rather than pearls. All material is hand cut and trimmed from the shell and carefully selected for pattern and color.
Gold-lip pearl is scientifically the same as “white” mother-of-pearl, only that gold is taken from the reverse side of the shell. Good quality dark gold shells come from the waters surrounding the Philippines and parts of Indonesia. Gold-lip shells will yield both gold pieces as well as colorful white pieces from the inside of the shell, though it is not desirable to have both colors showing on the surface of any one piece. Gold lip is priced based on depth of color and iridescence.
Black-lip pearl is probably one of the most exclusive pearls in demand in today’s knife and musical instrument market. It comes from small shells found in French Polynesia around Tahiti and its archipelagos. Just under the exterior bark of the shell is where the real beauty of the black-lip shell lies. Like gold-lip, black-lip has a black/grey color around the lip of the shell. Also, like gold-lip, black-lip is priced by the depth of color and iridescence. A nice pair of black lip will have every color of the rainbow in its iridescent black background. A pair is considered large if it has a usable area of 2 1/2″ x 7/8′ x .080″. Currently, black-lip is at an all-time low with regards to availability.
Red abalone is a very exclusive material that has a demand much greater than its supply. The red abalone shell comes from just off the northern California / southern Oregon coast. Its name is a bit deceiving, it isn’t red at all, but gets its name from the exterior bark which has a very red or pink tint. Most shells are not large enough to yield realistic knife handles. This, combined with their tendency to be full of holes created by boring sponges, makes for only about 2% of all abalone harvested worth using. Abalone has two areas that are of particular interest to knife makers. First, there is the lip section which has a bulls-eye type pattern where iridescent pools of color blend together in a random larger pattern. Second, the heart section has a tight pattern of different colors and reveals the illusion of depth on the surface. Other abalones include blue- green paua from New Zealand, awabi from Japan, and green abalone from Mexico and Southern California. Most of these rarely get large enough to make a full exposed handle, and are primarily used for inlays.
FOSSIL CORAL
It is important to understand “fossil coral” is a natural stone formed from ancient corals. It should not be mistaken for protected and endangered coral reef from the modern oceans of today. Fossil coral is a natural stone that is formed when ancient coral is gradually replaced with agate. The proper name for this material is agatized coral or agatized fossil coral. Agate, also known as chalcedony, is a type of cryptocrystalline quartz or silicon dioxide. Under unique geological conditions, prehistoric corals and mollusks can fossilize by being replaced with agate from silica-rich ground water percolating through limestone. The fossilized coral typically appears as small flower-like patterns in the stone.
Agatized fossil coral can exhibit a wide range of natural colors, ranging from white and pink to brown, gray, black, yellow and red. Corals may vary widely within a single stone depending on weathering and oxidation and the original mineral content.
Corals are among the most colorful animals in the sea. Most corals live in warm, shallow, tropical seas and feed on plankton. The oldest fossil corals are from the Ordovican period, over 450 million years ago. Corals are marine animals with a sac-like body, mouth, tentacles and skeleton. It is the skeleton that survives in the fossil record. Corals may be solitary or found in large colonies.
In some cases, corals were buried in sediment as crustal plate movements affected the land surface and as the oceans rose and fell. Temperature and pressure from compaction during burial resulted in those deposits becoming rock and part of the present day geological record.
Of the varieties of fossilized corals found throughout the world, exquisitely detailed specimens from the mountains of Indonesia are among the most unique. In Indonesia, entire coral heads are often completely preserved and appear just as they did 20 million years ago, although their density is much changed by replacement with silica, iron, manganese and other minerals. There are fern corals, brain corals, hex corals, honeycomb corals and many more.
For many years, ancient coral deposits have been mined for their high quality calcium, potassium, magnesium and sodium content which are used in health supplements. Fossil corals have been used for centuries in such other diverse places as fertilizers, building materials, and in filters to remove impurities such as chlorine and formaldehyde from water.
TITANIUM
HISTORY
The element titanium was discovered as a component of beach sands by a William Gregor in 1790. It was named titanium after titan, a giant in Greek mythology, by M.H. Klaproth in 1795. Since then, it has been widely studied, and the basic research for the development of the titanium industry have been accomplished with the magnesium reduction process of titanium tetrachloride invented by W.J. Kroll in 1938. In 1947 mass production of titanium metal was started by the us bureau of mines.
INTRODUCTION
Titanium is lightweight, the specific gravity is 4.5, which is approximately half and 60% those of nickel or copper and steel, respectively. Titanium melts at 3,045*f. Titanium can be tig and mig welded in inert gas. It is ductile only when it is free of oxygen. The specific strength (tensile strength per specific gravity) of titanium is 3 times that of aluminum and even higher than that of stainless steel. This superior property is maintained virtually at the same level even at a temperature of 500*c. Titanium is equivalent to platinum in resistance to corrosion by seawater and is mostly superior to stainless steel in corrosion resistance.
Titanium is present in meteorites and in the sun. Titanium oxide bands are prominent in the spectra of m-type stars. Titanium is the fourth most abundant structural metal and ninth most common element in the earth’s crust. It is refined from rutile (tio2) ores mined in the U.S., Australia, Africa, China, and Russia. Rutile is most commonly recognized as the gold fibrous crystals in rutilated quarts. Titanium is almost always present in igneous rocks and in the sediments derived from them. It occurs in the minerals rutile, ilmenite, and sphene, and is present in titanates and in many iron ores. Titanium is present in the ash of coal, in plants, and in the human body.
Titanium, when pure, is a lustrous, white metal. Titanium metal is considered to be physiologically inert. When pure, titanium dioxide is relatively clear and has an extremely high index of refraction with an optical dispersion higher than diamond. It is produced artificially for use as a gemstone, but it is relatively soft. Star sapphires and rubies exhibit their asterism as a result of tio2. Titanium dioxide is extensively used for both house paint and artist’s paint, as it is permanent and has good covering power. Titanium paint is an excellent reflector of infrared. Titanium oxide pigment accounts for the largest use of the element.
Due to its high strength (especially in the alloys) and light weight, titanium has many applications in the aerospace industry. Excellent corrosion resistance makes this metal highly desirable for chemical and food processing, also bone replacement and other body implants. This hypo-allergenic metal is safe for sensitive wearers.
Titanium is available in some 20 standard grades and alloys. Grade #1, commercially pure (cp) titanium is the best suited to jewelry applications. It is ductile and surprisingly slow to work harden. Although the other alloys and less pure grades will color, they are too hard for jewelry work. Titanium needs to be freshly etched to produce its most vivid colors.
Titanium may be either hot or cold forged. At approximately 1640*f titanium goes through a structural phase change and becomes very ductile. As it drops below this temperature it will suddenly harden. The main disadvantage to hot work is the build-up of very tough surface oxides. These are dark and may extend deep into the metal surface. They must be ground off and the surface finished before coloring.
COLOR
Reactive is a descriptive term used in connection with a family of metals that react to their environment. Titanium is one of the most common of these metals. They react by oxidizing, especially when excited with heat or electricity in an electrode. The colors produced by these metals are known as interference colors. There are no pigments or dies involved. They are generated by a transparent oxide film grown on the metal surface, which results in the appearance of color. The metal does not actually change color, rather the thin, transparent oxide generates interference colors. The colors develop when part of the light striking the surface reflects and part pass through the film to reflect off the metal below. When the delayed light reappears and combines with the surface light waves, they may either reinforce or cancel. This generates a specific color. The thickness of the oxide film dictates the color. In nature these colors can be found in the eddies of an oily wet street and in the iridescent colors of some insects. The colors are controlled by the voltage being applied through a bath, a brush or sponge.
All forming and surface finishing must be done before coloring. Most surface finishing techniques can be adapted to these metals. Finishing will be more time consuming than with traditional metals. Consideration should be given to sanded and textured surfaces. Light gathering scratches and marks will add flash and variety to the work. Textured surfaces add some protection against abrasion. Although harder than the parent metal, the extreme thinness of the oxide dictates that it is not a strong wearing surface. Items that normally receive heavy abrasion should not be considered unless the metals are protected by other design elements. Titanium requires a chemical etch to prepare the surface for high voltage anodizing.
Coloring can be achieved in two ways; thermal oxidation and electrolytic excitation, the metals react with oxygen to form a thin transparent film. Thermal oxidation (heat coloring) is simple, but difficult to control. Anodizing is infinitely more predictable and is the only effective way to control color. The colors produced appear in up to five repeating orders. Most of the current jewelry is produced within the first two orders. All the colors of the light spectrum are not produced. True red and forest green are not generated. When the oxide is of a thickness to generate interference colors, its depth is measured in angstroms (a=1/100,000,000 centimeter.) This layer can vary from 500 to 1,000a+ depending on the color. It is not the oxide itself that is perceived by the viewer, but its effect on light.
Anodizing most closely resembles standard electroplating. When a reactive metal is suspended in an electrolytic bath as an anode (+) and current is passed through the bath, oxygen is produced at the anode surface. This oxygen reacts with the metal to form a thin oxide film that generates colors. The transparent oxide increases in thickness in relation to the amount of voltage applied. At any given voltage the oxide will grow to a specific thickness (i.e. color) and stop, having reached a stage where current will no longer pass. This phenomenon of voltage controlled growth means that the color is also voltage controlled. An area of oxide produced with a high voltage will not pass current from a lower voltage. In other words, an area anodized at 60 volts will not need masking when an adjacent area is anodized to 40 volts. It follows that multiple anodizing processes should proceed in decreasing voltages. Working in descending order will save masking and generate fewer errors. While oxygen is generated at the anode (+), hydrogen is formed at the cathode (-). Titanium and stainless steel make most convenient cathodes. This process does not have much throwing power and it is necessary to have a cathode equal to or larger than the anode. The electrolytic solution can be almost any liquid capable of carrying current. Such diverse solutions as cola, sparex, sulfuric acid, ammonium sulfate (fertilizer), magnesium sulfate (epsom salts), trisodium phosphate, dish detergents and even wine will work. Recommended is a solution of 3 to 10% by weight trisodium phosphate (T.S.P.) in solution with distilled water. The percentage of chemicals in the solution will determine to some extent the length of time for the desired reaction to be completed. Slowing the reaction can be achieved by lowering the concentration of chemical in solution. The power supply required for anodizing has a much greater range of voltage control and lower range of current capabilities than plating rectifiers. The requirements are 0-150 volts dc variable in one volt increments and from 2-5 amps. Larger capacity power supplies may be necessary for work larger than jewelry and in high volume production.
