Properties & Information
Arfvedsonite
ArfvedsoniteSCIENCE / MINERALOGYArfvedsonite is a sodium-rich amphibole mineral, commonly dark blue-black to black, with the idealized formula NaNa₂(Fe²⁺₄Fe³⁺)Si₈O₂₂(OH)₂. It crystallizes in the monoclinic system and can show blue flashes or...
Arfvedsonite
ArfvedsoniteSCIENCE / MINERALOGYArfvedsonite is a sodium-rich amphibole mineral, commonly dark blue-black to black, with the idealized formula NaNa₂(Fe²⁺₄Fe³⁺)Si₈O₂₂(OH)₂. It crystallizes in the monoclinic system and can show blue flashes or...
Antlerite
AntleriteSCIENCE / MINERALOGYAntlerite is a copper sulfate hydroxide mineral with the formula Cu₃SO₄(OH)₄. It crystallizes in the orthorhombic system and usually occurs in bright to dark green acicular, prismatic, fibrous,...
Antlerite
AntleriteSCIENCE / MINERALOGYAntlerite is a copper sulfate hydroxide mineral with the formula Cu₃SO₄(OH)₄. It crystallizes in the orthorhombic system and usually occurs in bright to dark green acicular, prismatic, fibrous,...
Aragonite
AragoniteSCIENCE / MINERALOGYAragonite is one of the naturally occurring polymorphs of calcium carbonate, CaCO₃, sharing the same chemistry as calcite but having an orthorhombic crystal structure. It forms acicular crystals,...
Aragonite
AragoniteSCIENCE / MINERALOGYAragonite is one of the naturally occurring polymorphs of calcium carbonate, CaCO₃, sharing the same chemistry as calcite but having an orthorhombic crystal structure. It forms acicular crystals,...
Aquamarine
AquamarineSCIENCE / MINERALOGYAquamarine is the blue to blue-green variety of beryl, Be₃Al₂Si₆O₁₈. Its color is produced primarily by iron in different oxidation states within the beryl crystal structure. It crystallizes...
Aquamarine
AquamarineSCIENCE / MINERALOGYAquamarine is the blue to blue-green variety of beryl, Be₃Al₂Si₆O₁₈. Its color is produced primarily by iron in different oxidation states within the beryl crystal structure. It crystallizes...
Apophyllite
ApophylliteSCIENCE / MINERALOGYApophyllite is a mineral-group name commonly used in the gem and crystal trade for members such as fluorapophyllite-(K) and hydroxyapophyllite-(K). These hydrated potassium-calcium silicates typically form square or...
Apophyllite
ApophylliteSCIENCE / MINERALOGYApophyllite is a mineral-group name commonly used in the gem and crystal trade for members such as fluorapophyllite-(K) and hydroxyapophyllite-(K). These hydrated potassium-calcium silicates typically form square or...
Apache Tears
Apache TearsSCIENCE / MINERALOGYApache Tears are naturally rounded or nodular pieces of obsidian, a silica-rich volcanic glass. They are commonly black to dark brown and may appear translucent smoky brown...
Apache Tears
Apache TearsSCIENCE / MINERALOGYApache Tears are naturally rounded or nodular pieces of obsidian, a silica-rich volcanic glass. They are commonly black to dark brown and may appear translucent smoky brown...