What does idocrase mean?
Idocrase is a complex calcium-aluminum silicate mineral in the vesuvianite group. It is best known for forming well-developed prismatic crystals and for its remarkable range of colors, including green, brown, yellow, reddish, and occasionally purple. Some transparent or attractively colored specimens are cut or polished for use as gemstones, while others remain valued chiefly by mineral collectors. The name derives from Greek words meaning “form” or “appearance” and “mixing,” reflecting the mineral’s varied appearance and complex chemical composition. Although the term is sometimes used in association with vesuvianite, idocrase is the specific mineral name, whereas vesuvianite also serves as the group name. In ordinary writing, the word is uncommon and specialized, appearing mainly in descriptions of mineral specimens, collections, lapidary products, and the physical properties of crystalline rocks.
nounA complex calcium-aluminum silicate mineral belonging to the vesuvianite group. It commonly occurs as prismatic crystals in green, brown, yellow, and other colors, with attractive transparent varieties sometimes used as gemstones.
- A complex calcium-aluminum silicate mineral of the vesuvianite group, commonly forming green, brown, or yellow prismatic crystals; transparent attractive varieties may be used as gemstones.
"The collector displayed a rare green idocrase crystal under the museum lights."
"A small, finely formed idocrase was found among the quartz crystals."
"The jeweller described the vivid green idocrase as a rare gemstone suitable for a pendant."
Used when referring to multiple specimens, crystals, or occurrences of the mineral.
"Several exceptionally lustrous idocrases were displayed at the mineral exhibition."
Idocrase means “form of a mixture,” a fitting name for a mineral renowned for its unusually varied colors.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Etymology of idocrase
The name idocrase comes from Ancient Greek eidos, meaning “form” or “appearance,” combined with krasis, meaning “mixing” or “blending.” It was coined for a mineral whose varied colors and complex composition seemed to combine distinct appearances. The first element also underlies English words such as idea, identity, and isotope, while krasis has given English its word crasis.
How idocrase is actually used
The term is chiefly used in mineralogy and lapidary contexts. It names the mineral rather than the geographic place where a specimen was found.
Easily confused with idocrase
Idocrase is the mineral-species name, while vesuvianite is the name of its mineral group and was historically applied to the same material.