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Continue ShoppingGemstone Glossary C
Cacoxenite – Cacoxenite is an iron aluminium phosphate mineral that is associated with iron ores. The name comes from the Greek κăκός for “bad” or “evil” and ξένος for “guest” because the phosphorus content of cacoxenite lessens the quality of iron smelted from ore containing it. It occurs as a secondary phase in oxidized magnetite and limonite deposits.
Calcite – A carbonate mineral crystal that is colorless or white, also seen as grey, orange, yellow and green. Calcite is versatile and is formed as stalactites, granular, massive, and concretionary or rhombohedra structures. Calcite is often used for its optical properties, with one of the most interesting being by Trilobites; they used clear calcite crystals to form the multiple lenses of their eyes.
Calcoprite – Chalcopyrite is a copper iron sulfide mineral that is brassy to golden-yellow in color with a strong metallic sheen. As with copper, this mineral oxidizes with air exposure and it quite brittle.
Carnelian – Carnelion is a form of chalcedony which is brownish red to orange and is a trigonal crystal. The coloring in carnelion is created by trace amounts of iron oxide.
Cat’s Eye Spectrolite – Cats eye spectrolite is an extremely rare variety of feldspar related to labradorite. Forming as violet, blue or green generally, this mineral can also be found, rarely, in a bronze-red color and features a single asterism that resembles the patterning of a cat eye.
Cavansite – Cavansite is a calcium vanadium silicate mineral forming as a brilliant blue to greenish, brittle prismatic or rosette crystal. Cavansite is relatively rare and was first discovered in Oregon in 1967.
Celestial Quartz – Clear quartz enhanced with various natural elements such as titanium, gold, indium, etc. to give the stone a more iridescent and prismatic color effect is known as Celestial Quartz.
Charoite – Charoite is a rare silicate mineral that became known to the gemstone market in 1978 and is found solely in Siberia, Russia. Charoite is lavender to violet in color and displays a chatoyant swirl pattern.
Chiapas Amber – Chiapas amber is found in the Southern State of Chiapas, Mexico and is also called Mayan amber. Amber is a resin (not sap) that has fossilized over millions of years. Chiapas amber is dated at approximately 25 million years old and is one of the only ambers offered that is not treated in any way. As with many ambers, Chiapas amber can be found with fossil insect inclusions and can be completely transparent.
Chiastolite – An Andalusite that shows an impressive cross when dispayed as a polished cross section cut of the natural rhombic crystals. Sometimes referred to as Cross Stone, Chiastolite is most often seen as a mixed brown background with a very deep brown cross.
Chinese Writing Stone – Chinese writing stone is a limestone matrix with andalusite crystals. The patterns of dark grey to green and creamy white resemble chinese characters, hence its name. Chinese writing stone can be found in California’s Sierra Nevada foothills, and is actually different than Chrystanthemum stone, though people often confuse the two.
Chocolate Jasper – Jasper that displays monochromatic bands of varying mocha brown hues is known as chocolate jasper, or coffee jasper.
Chrome Diopside – Diopside is a silicate mineral that forms variably colored, but typically green crystals. Its coloration is a rich olive toned green that has an almost glass like appearance. Chromium Diopside localities within the US include California, Colorado and Wyoming. Gemstone quality Diopside is either Black Star or Chrome Diopside.
Chrysocolla – Chrysocolla refers to a copper silicate and covers a great span of varieties, mostly displaying patterns of blue and green.
Chrysoprase – Chrysoprase is the green gemstone variety of chalcedony that ranges in color from sea foam to apple or dark greΩen.
Cinnabar – Cinnabar, a sulfide mineral, is the common ore of mercury. Generally a bright scarlet to brick red color, it can also be seen in a brownish red and lead grey color. Cinnabar is found in all localities that yield mercury, and is still being deposited presently from Steamboat Springs, NV and the hot waters of the Sulphur Bank Mine in CA. Despite the toxicity of its mercury level, it can be safely used in jewelry by the replacement of its toxic pigment to a resin-based polymer.
Citrine – Citrine is named after the French word for lemon, “citron” and ranges from yellow to orange-brown. Citrine is a variety of quartz and is created from heated amethyst. The heating process which turns purple amethyst to orange citrine can happen naturally or by man. The official birthstone for November since 1912, Citrine is also a common reference to color in gemstones as well as animals, such as the Citrine Canary.
Cobalto-Calcite Drusy – A natural pink drusy discovered only in the mid-1990s in Zaire, this African stone ranges in saturation from a delicate pale pink to vibrant hot pink. Pink is one of the rarest colors in the gem world, and drusy has recently become increasingly popular sparking a high demand, making Cobalto-Calcite, or Pink Dolomite, a stand out amongst natural stones.
Coffee Jasper – Jasper that displays monochromatic bands of varying mocha brown hues is known as chocolate jasper, or coffee jasper.
Copper – Copper is a reddish-orange, soft metal. It is a chemical element with the symbol (Cu). Copper is highly conductive for electricity and heat and is often used for marine pipes. While copper that is freshly exposed is reddish-orange, it can oxidize and change color with exposure to air or heat.
Copper in Quartz – Copper veins that run through a quartz matrix creating a contrasting metallic web pattern.
Crazy Lace Agate – XXX
Cuprite – A copper oxide mineral this is dark red and sometimes almost black. Cuprite crystals are cube like and generally too small to cut faceted stones, aside from one unique mine in Africa which produced large gem quality crystals. Cuprite is sometimes known as Ruby Copper and gets its name “Cuprum”, the Latin word for copper.