Mohs 6.5
Vickers (~) 820 HV
Knoop (~) 870 HK
Geological setting
MetamorphicSkarn
Element composition by mass
Formula: Ca₂Al₃(SiO₄)(Si₂O₇)O(OH) · molar mass: 454.35 g/mol
| O | 45.78% | |
| Si | 18.54% | |
| Al | 17.82% | |
| Ca | 17.64% | |
| H | 0.22% |
Computed from atomic weights (IUPAC 2021). Site-occupancy groups (Fe,Mn) split equally.
Mohs Hardness
6.5
Clinozoisite sits at 6.5 on the Mohs scale — harder than glass; scratches steel.
Colors:
Streak
White
White
Crystal system
Monoclinic
Monoclinic
SilicatesSilicates (Sorosilicates)
TL;DR · 1 min read
Clinozoisite (Ca₂Al₃(SiO₄)(Si₂O₇)O(OH)) is the monoclinic counterpart of orthorhombic zoisite — same chemistry, different crystal system. It is closely related to epidote but has lower iron content.
Clinozoisite (Ca₂Al₃(SiO₄)(Si₂O₇)O(OH)) is the monoclinic counterpart of orthorhombic zoisite — same chemistry, different crystal system. It is closely related to epidote but has lower iron content. Clinozoisite forms in low-grade metamorphic rocks and contact-aureole skarns. Italian Alps and Japan yield gem-quality material.