Mindblown: a blog about philosophy.

Citrine’s name derives from its lemon yellow color, and from the old French word citrine, meaning “lemon.” It is a yellow to brownish quartz (silicon dioxide) and resembles yellow topaz. Citrine has been popular for thousands of years and revered for its rarity. Citrine occurs in igneous and metamorphic rocks, particularly in granite and gneiss.…

Chrysoprase is considered the most valuable stone in the chalcedony group; with a translucent apple-green color.  Its name derives from the Greek chrysos and prason, meaning “golden leek,” and was probably applied originally to a lighter or more yellowish chrysoprase.  The microscopic fine quartz fibers have a radial structure. The coloring agent is nickel. Chrysoprase…

Chrysocolla is a basic copper silicate composed of a mix of various microscopic crystals found in a variety of colors.  It has a greasy vitreous luster.  The name chrysocolla originated in ancient times, and was applied by the Greek philosopher Theophrastus in 315 BC to various materials used in soldering gold.  The name is derived from…

Chalcedony is a variety of microcrystalline quartz (silicon dioxide), often with some iron and aluminum.  It is composed of microscopic fibers.  Chalcedony is found in veins, geodes, and concretions.  It can be mammillary, botroyoidal, or stalactitic.  Chalcedony is found in numerous locations throughout the world. Its name may derive from the ancient port of Khalkedon…

Celestine is named after the Latin word caelestis, meaning “heavenly.”  It is a mineral consisting of strontium sulfate. The mineral is named for its occasional delicate blue color. Celestine occurs as crystals, and also in compact massive and fibrous forms. It is mostly found in sedimentary rocks, and often associated with the minerals gypsum, anhydrite,…

Cat’s eye is also known as “chrysoberyl cat’s eye,” or cymophane, from the Greek – waving light.  All other cat’s eye is designated with a different name.  Cat’s eye forms fine parallel inclusions that produce a silver-white line that appears as a moving light ray in a cabochon cut stone; resembling the pupil of a cat.  The…

Calcite is the most common form of calcium carbonate. It is known for its great variety and the beautiful development of its crystals. Calcite is also called limespar. The name is derived from the Latin word calx, meaning “lime.” More than 300 forms of calcite crystals are known, and they combine into a thousand different…

At Gemstoneindex you can find information on gemstones, minerals, jewelry, birthstones and more. It is intended as a guide to the beautiful and fascinating world of gemstones. Throughout history gemstones have been admired and worn as amulets and talismans; believed to have powers to protect against evil, disease, and as safeguards of health. Gemstones have…

At Gemstoneindex you can find information on gemstones, minerals, jewelry, birthstones and more. It is intended as a guide to the beautiful and fascinating world of gemstones. Throughout history gemstones have been admired and worn as amulets and talismans; believed to have powers to protect against evil, disease, and as safeguards of health. Gemstones have…

At Gemstoneindex you can find information on gemstones, minerals, jewelry, birthstones and more. It is intended as a guide to the beautiful and fascinating world of gemstones. Throughout history gemstones have been admired and worn as amulets and talismans; believed to have powers to protect against evil, disease, and as safeguards of health. Gemstones have…