Calcite
Calcite
Named for its calcium content, calcite is one of Earth's more abundant minerals-- you've probably seen it many times and not known exactly what it was. It is found in marble and limestone, as well as other rocks used in industrial settings. Gem-quality calcite, however, takes on a quite different look. You may have seen colorless calcite crystals used as examples for double refraction, but it also forms as white, gray, yellow, pink and green gems. Material is often faceted or polished en cabochon, or carved into ornamental objects.
General Information
LWUV: Variable
Calcite Colors
-
Black -
Blue -
Brown -
Brown -
Colorless -
Gray -
Green -
Multi-color -
Orange -
Pink -
Pink -
Purple -
White -
Yellow
Alternate Names
Iceland Spar
Countries of Origin
Tanzania, United Republic Of; Afghanistan; Russian Federation; United States of America; Madagascar; United Kingdom of Great Britain and Northern Ireland; Portugal; Iceland; Greece; Austria; Latvia; Sweden; Pakistan; Morocco; Unknown; China; Ireland; Brazil; Slovakia; Bulgaria; France; Colombia; Argentina; Republic of Kosovo; Switzerland; Bolivia (Plurinational State of); India; Spain; Canada; Belgium; Norway; Namibia; Congo (the Democratic Republic of the); Faroe Islands; Italy; Mexico; South Africa; Australia; Peru; Germany
History
Like so many minerals, calcite is found abundantly throughout the earth. It's found in marble and limestone, and sometimes in the rocks that cover our driveways. Gem-quality calcite is MUCH rarer, and significantly lovelier than its more ordinary family members. It's found in colorless, white, gray, yellow, pink, and green shades. Gem-quality calcite often appears translucent. Because it's so lovely, we are drawn to it as adornment. We recommend you wear and treat calcite with care because it is a 3 on the Mohs scale.
Care
Calcite is very soft, so be mindful of scratching. It is easily attacked and dissolved by acids such as vinegar. Avoid abrasives, ultrasonic, solvents and heat. Calcite is generally unsuitable for jewelry.
Species/Variety
Cobaltocalcite
Cobaltocalcite refers to a stunning pink-red to slightly purplish-red cobalt-rich calcite mineral.
Iceland Spar
The colorless, transparent variety of calcite is called "Iceland spar," an important variety for its use in optics, including gemological dichroscopes. Originally discovered in the Helgustadir Mine, Eskifjord, Iceland, gems are most often sold as cleavage pieces that beautifully demonstrate calcite's unique birefringence, or double refraction. When unpolarized light enters a piece of calcite the light will split into two rays. When a block of calcite is placed on text the words will appear to double. It has been proposed that Iceland spar is the legendary Viking sunstone. Early navigators used calcites polarizing effect of light to detect the direction of the sun on cloudy days.
