Crystals
Anthophyllite
Anthophyllite • orthorhombic magnesium–iron amphibole Idealized composition: Mg7Si8O22(OH)2 Iron-rich relative: ferro-anthophyllite Al-rich compositions grade toward gedrite-related amphiboles Cleavage: approximately 56° and 124° Mohs 5.5–6 • specific gravity commonly 2.85–3.2 Habit:...
Anthophyllite
Anthophyllite • orthorhombic magnesium–iron amphibole Idealized composition: Mg7Si8O22(OH)2 Iron-rich relative: ferro-anthophyllite Al-rich compositions grade toward gedrite-related amphiboles Cleavage: approximately 56° and 124° Mohs 5.5–6 • specific gravity commonly 2.85–3.2 Habit:...
Ametrine
Ametrine • natural or synthetic bicolor quartz containing amethyst and citrine-colored sectors Composition: SiO2 with iron-related color centers Colors: violet to purple and yellow to golden orange Crystal system: trigonal...
Ametrine
Ametrine • natural or synthetic bicolor quartz containing amethyst and citrine-colored sectors Composition: SiO2 with iron-related color centers Colors: violet to purple and yellow to golden orange Crystal system: trigonal...
Zoisite
Zoisite · orthorhombic calcium-aluminum sorosilicate and polymorph of clinozoisite Ca₂Al₃(SiO₄)(Si₂O₇)O(OH) IMA symbol · Zo Tanzanite · blue-to-violet, vanadium-bearing gem zoisite Thulite · pink manganese-bearing zoisite Anyolite · ruby-bearing green zoisite...
Zoisite
Zoisite · orthorhombic calcium-aluminum sorosilicate and polymorph of clinozoisite Ca₂Al₃(SiO₄)(Si₂O₇)O(OH) IMA symbol · Zo Tanzanite · blue-to-violet, vanadium-bearing gem zoisite Thulite · pink manganese-bearing zoisite Anyolite · ruby-bearing green zoisite...
Sugilite
Sugilite · lithium-bearing double-ring silicate of the milarite–osumilite structural family KNa₂(Fe³⁺,Mn³⁺,Al)₂Li₃Si₁₂O₃₀ Hexagonal · rare crystals, commonly granular to massive Purple color · principally associated with Mn³⁺ in gem material Mohs...
Sugilite
Sugilite · lithium-bearing double-ring silicate of the milarite–osumilite structural family KNa₂(Fe³⁺,Mn³⁺,Al)₂Li₃Si₁₂O₃₀ Hexagonal · rare crystals, commonly granular to massive Purple color · principally associated with Mn³⁺ in gem material Mohs...
Scolecite
Scolecite · calcium-bearing zeolite of the natrolite subgroup CaAl₂Si₃O₁₀·3H₂O Monoclinic · commonly pseudotetragonal in outward form Mohs 5–5.5 · brittle despite its moderate hardness Radiating sprays · slender prisms ·...
Scolecite
Scolecite · calcium-bearing zeolite of the natrolite subgroup CaAl₂Si₃O₁₀·3H₂O Monoclinic · commonly pseudotetragonal in outward form Mohs 5–5.5 · brittle despite its moderate hardness Radiating sprays · slender prisms ·...