Phyllosilicates - Sorosilicates

Sorosilicates

Sorosilicates (from Greek σωρός sōros, heap, mound) have isolated double tetrahedra groups with (Si₂O₇)6− or a ratio of 2:7. Nickel-Strunz classification: 09.B

• Hemimorphite (calamine) - Zn₄(Si₂O₇)(OH)₂·H₂O
• Lawsonite - CaAl₂(Si₂O₇)(OH)₂·H₂O
• Ilvaite - CaFe2+₂Fe3+O(Si₂O₇)(OH)
• Epidote group (has both (SiO₄)4− and (Si₂O₇)6− groups)
  • Epidote - Ca₂(Al,Fe)₃O(SiO₄)(Si₂O₇)(OH)
  • Zoisite - Ca₂Al₃O(SiO₄)(Si₂O₇)(OH)
  • Clinozoisite - Ca₂Al₃O(SiO₄)(Si₂O₇)(OH)
  • Tanzanite - Ca₂Al₃O(SiO₄)(Si₂O₇)(OH)
  • Allanite - Ca(Ce,La,Y,Ca)Al₂(Fe2+,Fe3+)O(SiO₄)(Si₂O₇)(OH)
  • Dollaseite-(Ce) - CaCeMg₂AlSi₃O₁₁F(OH)
• Vesuvianite (idocrase) - Ca₁₀(Mg,Fe)₂Al₄(SiO₄)₅(Si₂O₇)₂(OH)₄