Stone Info_Organics & Collector Stones .pdf

******Organics and Collectors’ Stones******** LARGEST CONSUMERS : Amber: China demand is strong, Pieces containing insect or plant inclusions fetch higher prices than inclusion-free pieces Ivory: Chinese have always prized ivory, but now have moved towards mammoth Moldavite: very popular in the Chin...

******Organics and Collectors’ Stones******** LARGEST CONSUMERS : Amber: China demand is strong, Pieces containing insect or plant inclusions fetch higher prices than inclusion-free pieces Ivory: Chinese have always prized ivory, but now have moved towards mammoth Moldavite: very popular in the Chinese market MOHS SCALE: Amber: is soft , 2 to 2.5 Coral: Soft, 3.5 , toughness is fair to good Ivory: rates about 2.25 to 2.75 Shell: 3.5 Tortoise Shell: fairly soft 2.5, but it’s fairly tough Jet: hardness falls between 2.5 and 4 Apatite: low hardnes, 5, with cleavage issue preventing it form being cut above 5ct Benitoite: 6.5 Fluorite: low hardness, easy cleavage in four directions Kyanite: hardness in different directions, 7 across the crystal and about Mohs 5 along its length Moldavite: hardeness 5 to 6 Obsidian: 5 to 5.5 Sphene: low hardness—5 to 5.5 COLOR/HUE RANGE/VALUE: Amber: transparent to opaque, and it’s amorphou, its polish luster is resinous—like plastic—to vitreous—like glass, yellow and golden amber, the gem can be white, orange-to-red, or brown. Transparent red amber is more valuable than golden amber, which is more valuable than yellow amber, strong fluorescence can give amber a bluish or greenish appearance Coral: Calcareous coral is semi-translucent to opaque, and its polish luster is waxy to vitreous, white, cream, pink, various shades of red and orange, blue, purple, and a light grayish violet called “lavender” in the trade, most valuable red coral is an intense red, light vivid pinks is also valued -Conchiolin coral: Black Coral , golden coral which displays a speckled golden sheen when polished,Golden coral is more rare than black coral Ivory: polish luster is greasy to dull, New ivory is white to light yellow, and translucent to opaque,best African elephant ivory shows a warm, mellow tint with little grain or mottling, tends to yellow with age Shell: polish luster is greasy or pearly, mother-of-pearl -Abalone: black, colors include various tones and saturations of red, pink, orange, yellow, green, brown, and blue, Many colors appear as patterns that resemble contour lines on a map -Helmet Shell: layers of contrasting colors that differ among species, the most used is the bullmouth helmet shell-brownish red outside, white in the middle layer, and light brown to brownish orange, or tawny red, on the inside, often used for cameos Queen Conch shell: is rose-colored on the outside and has a large, flaring lip that’s a rich pink, orange, and yellow on the inside. Some shells show a flame-like structure, often carved into cameos with white on a rosecolored background or rose-colored on a white background Ammonite: range from gray to brown and sometimes show iridescent flashes of red, green, orange, & purple Tortoise Shell: dark amber color with radiating streaks of brown or black, Rich brown mottling often decorates the deep yellow background, semitransparent to translucent,polish luster is resinous to waxy Jet: intensely black and takes a high polish resinous to vitreous polish luster, semitranslucent to opaque Apatite: neon blue, also can be yellow, green, violet, purple, blue, pink, brown, or colorless Benitoite: transparent stone that can be blue or violetish blue, light blue, colorless, or white zoning,strong blue and colorless pleochroism, strong fire, rare circumstances, the gem can be pink COLOR/HUE RANGE/VALUE continued: Fluorite: transparent-to-translucent, green, blue, brown, yellow, orange, pink, purple, violet, or colorless. Kyanite: Or "disthene", transparent-to-translucent, and usually ranges in color from light to dark blue to green, (resembles sapphire) can sometimes be yellow, gray, brown, or colorless, Fashioned gems are typically zoned with blue, green, or colorless bands, facet cut for collector, but due to rarety and toughness issue typically nit found in jewelry Moldavite: medium to dark yellowish to grayish green,smooth, scarred, or pitted surfaces. They vary from simple rounded shapes to intricate natural sculptures. Obsidian: gray to black—often spotted with white—brown to brownish yellow, orange, or red. Rarely, it might be green, blue, or purple, transparent to opaque, and sometimes has a sheen Sphene: transparent to translucent, and can be yellow, green, brown, orange, or rarely, red FORMING SOURCE: Amber: hardened tree resin and being up to 120 million years old to thousands of years old, It has to be at least a million years old to be called amber - Copal: is less then a million years old and is softer than amber and melts at a lower temperature Coral: "coral polyps", as the animals are called, the skeleton is external. There are two basic types of gem coral —calcareous coral and conchiolin coral, both are the skeletal remains of tiny marine-animal colonies,they secrete it as small, needle-like structures, or spicules, of calcite. The spicules form a framework for the boneless coral polyp colonies to cling to creating coral Ivory: Asian and African elephant tusks,tusks are essentially teeth,amorphous, and heat causes it to shrink and discolor,sections show a pattern called “engine turning,”Others are the tusks of walrus, boar, and narwhal—a small whale species—and the teeth of the hippopotamus and sperm whale Ammonite: fossilized remains of hard-shelled, squid-like marine mollusks that lived between 65 million and 395 million years ago Tortoise Shell: actual shell of the Atlantic hawksbill sea turtle who resides most tropical and subtropical seas worldwide and live on coral reefs and in shallow coastal areas and lagoons, Magnified, natural tortoise shell shows many small dots (spherical particles) in a random pattern Jet: lignite coal that formed when wooden logs washed out to sea and sank into mud on the sea floor,logs became impregnated with oil formed by algae and plankton as they decayed in the mud developing jet COMMON TREATMENTS: Amber: can clarify cloudy amber by carefully heating it in rapeseed, or canola, oil which fills the bubbles ans removes cloudiness, (occasionally resulting in crack-like, circular marks called "sun spangles"), staining amber to make it look more aged (red) or dye to produce green amber -"Ambroid" or reconstructed or pressed amber are how large pieces of amber are made by pressing small, gem-quality pieces or chips together under gentle heat & pressure Coral: dye light calcareous coral red or pink to darker colors of more value, impregnated to improve luster or dyed and impregnated to improve color and color durability,dipping in melted wax improves its surface appearance -golden coral can be the result of treatment- the treated coral has a coarser texture than natural, black coral bleached and coated with relatively thick layers of artificial resin to protect the coral and intensify its color Ivory: bleach ivory to lighten it and remove stains (sunlight is sometimes used but can cause cracking), dyed to give it an antique appearance Shells: commonly dyed to produce a variety of colors, coated to improve its appearance Tortoise Shell: larger tortoise shell specimens by pressing small pieces or chips together under gentle heat and pressure. The product is called laminated tortoise shell Fluorite: Black to dark blue fluorite can be heated to a more attractive blue color. Colorless specimens can be irradiated to violet, but the color isn’t stable and fades quickly COMMON CUTS: Amber: Cabochon, beads and carvings Coral: beads, cabochons(round and ovals), carvings, and cameos, most produce beads between 2 and 6 mm Ivory: carvings, cabochons, beads, and bangle bracelets Shells: cameos, carvings, beads, cabochons, and inlays in decorative objects Ammonite: Cabochons, free forms, tablets, ovals, and squares, sometimes create doublets or triplets, doublets are paired with synthetic quartz, triplets adds a hard base made of manmade resin Tortoise Shell: inlaid hawksbill shell pieces with gold, silver, or mother-of-pearl in floral and geometric patterns,jewelry and other ornamental and utilitarian pieces, like hairbrushes, mirror frames, and combs Jet: Popular as mourning jewelry in the late Victorian era, beads, buttons, carvings, faceted pieces, and cabochons, antique pieces from the Victorian era, and cameos are especially prized Benitoite: Strong but rare its only set in high-end jewelry, mostly found 1ct, 2ct and 3ct are rare Fluorite: beads and carvings, mounted crystals for "new age" pendants Moldavite: faceted into brilliant and step cuts in a variety of sizes, or they are set as natural uncut piece Obsidian: carvings, beads, and faceted cuts, most used in jewelry are sheen obsidian and snowflake obsidian, Sheen obsidian typically has a golden or silver sheen that’s caused by light reflecting from minute inclusions, while snowflake obsidian is black with a distinctive pattern of white markings that resemble snowflakes Sphene: has very obvious fire, and so it is cut brilliant-cut and mixed-cut styles to emphasize that COUNTRIES OF ORIGIN: Amber: Baltic Sea region of Europe is the world’s leading amber source(Finest), Dominican Republic produces the second greatest volume of amber, Germany, Lithuania, Poland, and Russia, Denmark, Mexico, Alaska, and Myanmar’s Kachin State are also commercial amber sources Coral: Mediterranean Sea has been coral’s principal source(white, pink and deep red), Artisans from the Italian city of Naples have fashioned and marketed Mediterranean coral for centuries, Japanese, Malaysian, and Filipino waters also,Taiwan produces pink and red coral for its domestic market, Ivory: Asian and African elephant tusks were the origin source, but was made illegal by CITES in the the 1970s, mammoth tusks that have been frozen in Arctic ice mostly found in Siberia, Russia - Conchiolin Coral: Black Coral is from Queensland, Australia, and the US state of Hawaii, Golden Coral is from Hawaii and Tasmania, Australia Ammonite: Canada, England, Morocco, and the US. Canada is the main source of iridescent ammonites Tortoise Shell: Hawksbill turtles have been protected since 1975, and trafficing is a federal crime in the US since 1970, However, some material comes from the Caribbean, where the trade bans are largely ignored Jet: England is the major jet source. The English town of Whitby in Yorkshire is especially closely associated, other source Canada, France, Germany, Spain, and the US Apatite: Madagascar, Brazil, Mexico, and Myanmar are major sources, Other sources are Canada, the Czech Republic, Slovakia, Germany, India, Mozambique, Norway, South Africa, Spain, Sri Lanka, & the US Benitoite: just one location—the Diablo Mountain Range of San Benito County, in the US state of California, Fluorite: China, England, Switzerland, and the US are major sources of fluorite. Australia, Germany, Mexico, Namibia, and Norway are minor sources Kyanite: sources include Brazil, India, Kenya, Myanmar, Pakistan, Switzerland, the US, and Russia Moldavite: Some scientists believe that tektites formed when meteorites struck the earth and that moldavites found in western Moravia near the Moldau River are material ejected from a crater 186 miles away in present-day Germany, Other scientists believe that tektites originated in volcanic eruptions in the crater Tycho on the moon and fell to earth Sphene: Austria, Brazil, Canada, France, Madagascar, Mexico, Myanmar, Sri Lanka, Switzerland, the US, and Russia are sources of sphene. CHEMICAL COMPOSTION: Amber: carbon, hydrogen, and oxygen, with traces of sulfur Coral: Calcareous coral is calcium carbonate—a chemical compound containing calcium, carbon, and oxygen— in the form of calcite, Black coral main component is protein not calcium carbonate Shell: Calcium carbonate Ammonite: chemical composition of ammonites varies but is often made up of aragonite, calcite, pyrite, silica, and other minerals Tortoise Shell: protein similar in makeup to horns, claws, and fingernails Jet: amorphous lignite coal Apatite: calcium, phosphorous, and chlorine, found in pegmatites Benitoite: silicate of barium and titanium Fluorite: made of elements calcium and fluorine, and has a cube-shaped crystals,easy octahedral cleavage Kyanite: aluminum silicate with traces of titanium and iron producing it's color Moldavite: amorphous natural glasses, type of "tektite", Tektites are irregularly and sometimes intricately shaped glassy nodules and blobs containing gas bubbles Obsidian: amorphous, and mostly made of silicon dioxide, Iron and magnesium cause obsidian’s dark green to black colors Sphene: is a silicate of calcium and titanium (and so it is also called "titanite"), and iron, rare earth elements cerium and yttrium are also often present, and cause the yellow to yellowish green colors. Chromium causes the intense green of chrome sphene. TRADES NAMES: Coral: "oxblood"in English or Italian "rosso scuro", "arciscuro", pink coral “pelle d’angelo, vivid pink is "salmon" - Conchiolin coral: Black coral is also "King" or "Akabar coral" or "Horn Coral" Abalone Shell: Maori name "paua" Ammonite: are also marketed as “ammolite” and “korite.” MAIN SYNTHETIC PROCESS: n/a COMMON IMITATION MATERIAL: Amber: Copal natural imitator, while "Bakelite", a plastic, is probably the most prevalent artificial imitator, "Casein" made of celluloid, epoxy, glass, and polyester, imitations also contain insects, embedded by hand Coral: Calcareous coral is one of the most imitated organic gems. Glass, porcelain, and various plastics are the most common coral imitations, "Gilson" imitation coral made from calcite and silica, and probably colored by iron oxide, but lacks the wood-grain-like structure lines of natural coral,corozo nuts are stained red or pink then made into rounded beads to mimic Mediterranean coral. Ivory: Celluloid is the most common manufactured ivory imitator,plastics and fine plaster of Paris, Bone is a common ivory imitator such as long bones from oxen and jawbones from whales (easy to identify by seeing the canals when viewing a cross section) Deer horn or stag horn, seeds from the vegetable ivory: corozo nuts or tagua nuts, nuts from the doum (or doom) palm’s fruit is the other vegetable-source ivory imitator Shells: Molded glass and plastic are among the most common materials used to imitate shell cameos Tortoise Shell: Celluloid, casein, and Bakelite plastics imitate the shell well, Plastic usually has a regular and repeating pattern Jet: Cannel and anthracite, although more brittle, are other types of coal that often substitute for jet. Vulcanite— a hard, vulcanized rubber—imitates jet, as do glass, obsidian, dyed black chalcedony, and various plastics. “Paris jet” is actually black glass Moldavite: manmade glass specimens are etched with acid CLARIETY CHARACTERISTIC : Amber: Flower parts, leaves, pine needles, insects,gas bubbles,larger animals like scorpions, snails, frogs, and lizards can be very valuable, oxidation can cause amber to darken (yellow to red to black) Moldavite: specimens are spherical with few included bubbles, or flattened with far more included bubbles Obsidian: CRYSTAL STRUCTURE: N/A POSSIBLE PHENOMENA: Shells: Orient Apatite: Cat’s-eye apatite is semitransparent to translucent, and usually green or yellow Kyanite: can show chatoyancy,color-change effect from blue-green to greenish violet in daylight to red or reddish violet in incandescent light HISTORY: Fluorite: Blue John" or "Derbyshire spar, is the massive crystalline variety of fluorite used for thousands of years for vases and other decorative objects and was found in Derbyshire, England, but now that source is exhaust Obsidian: In prehistoric times, people used obsidian for spear points, knives, and tools because it breaks easily into sharp-edged flakes. CUTTING/TRADING CENTER: Helmet Shell: Naples region fashioned the finest helmet shell cameos, Asian manufacturers cut the majority of smaller, less expensive cameos VARIETY/SPECIES/GROUP: n/a