Mindblown: a blog about philosophy.

Malachite is a common secondary mineral with a vivid green color; formed by the gathering of copper deposits, where it is usually accompanied by lesser amounts of azurite, that have a deep azure blue color. It is normally found in opaque green masses that are granular, knobby, and massive. Malachite’s name derives from the Greek…

Labradorite is a colorful stone that offers a range of colors and optical effects. It is named after its source the Peninsula of Labrador in Canada, where it was found. Labradorite displays a metallic rainbow effect similar to that of black opal except with larger color spots, often blue and green, although specimens with the…

Kyanite’s name derives from the Greek kyanos, meaning “dark blue.” It occurs in metamorphic rocks such as schist and gneiss associated with garnet, staurolite and micas; and in eclogites. The presence of kyanite in rocks indicates that they have undergone moderate temperatures and medium to high pressures during metamorphism. Associated minerals include andalusite, corundum, and…

Jet is a hard gem variety of lignite (a type of coal), which is often carved or faceted, and takes a good polish. Jet has high carbon content and a layered structure. It is black to dark brown, and sometimes contains tiny inclusions of pyrite, which have a metallic luster. Jet’s name derives from the…

Jasper is usually considered as chalcedony.  Geologists sometimes put it in a group by itself within the quartz group because of its grainy structure.  The name jasper is derived from the Greek word “iaspis, which means “spotted stone.”  It incorporates various amounts of materials that give it both its opacity and color.  Brick-red to brownish-red…

There are two different minerals known as jade.  They are “nephrite,” which is an amphibole, and “jadeite,” which is a pyroxene.  Nephrite is the most common and widespread.  It is formed of a mat of tightly interlocking fibers, creating a stone tougher than steel.  It was used in China and New Zealand for tools and…

Fluorite is also called fluorspar, from the Latin word fluere meaning “to flow.” It is a widely distributed mineral that is mined in great quantities. It occurs in mineral veins, alone or as a gangue mineral with metallic ores and in association with quartz, barite, calcite, celestine, dolomite, galena, cassiterite, spalerite, topaz and many other…

Emerald’s name derives from the Greek word smaragdos, which in turn was derived from an earlier Persian word meaning green mineral. Emerald is a beryl, and is the best known variety of beryl.  Some of the world’s finest emeralds come from Colombia. Emeralds were mined by the Aztecs and also by the Incas over 500 years…

The most precious of the four precious stones, including emeralds, rubies and sapphires; diamonds are the hardest substance in the universe. Its name derives from the Greek word adamas, meaning invincible. The diamond is the only precious stone that rates a number ten in Moh’s scale of hardness. Made of pure carbon the only thing…

Coral polyps are marine plant-like animals and are extremely small, barely 2 millimeters in diameter. Coral’s external skeletons mass together to form tree like structures. They live in colonies, either in reef systems in warm, shallow water or in deep sea colonies. Coral polyps have a hollow cylindrical body, with a ring of tentacles around…