Clinozoisite is a common member of the epidote group typically found in low to medium-grade metamorphic rocks. It often forms elongated, prismatic crystals or fibrous aggregates and is distinguished from its green cousin epidote by its usually lighter, paler coloration.
Is this clinozoisite?
5-step field checkRun through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.
- 1Test the hardnessTry to scratch clinozoisite with a known reference. Clinozoisite sits at Mohs 6.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: grayish white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: colorless, green, gray, yellow green, light yellow.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: fibrous, massive, prismatic.
Often confused with
Clinozoisite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside clinozoisite
Minerals reported to co-occur with clinozoisite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₂Al₃Si₃O₁₂(OH)
- Mohs hardness
- 6.5
- Density
- 3.21-3.38 g/cm³
- Streak
- Grayish white
- Luster
- Vitreous
- Transparency
- Transparent to translucent
- Crystal system
- Monoclinic
- Crystal habit
- Fibrous, massive, prismatic
- Cleavage
- Perfect on {001}
- Rarity
- Common
- Uses
- Collector, Geological study
- Host rock
- Typically in low- to medium-grade regionally metamorphosed igneous and sedimentary rocks, as well as in contact metamorphosed calcium-rich sediments; an alteration product of plagioclase feldspars (saussuritization)
Where rockhounds find clinozoisite
2 mapped spotsClassic worldwide localities
- Belvidere Mountain quarries, Lowell, Orleans Co., Vermont, USA
- Northern Spade Spring Canyon, Los Angeles Co., California, USA
- Nightingale district, Pershing Co., Nevada, USA
- Goslarwand, near Prägraten, Tirol, Austria
- Vernirovice, Czech Republic
- Kälviä, Finland
Field-hunting tip
Where it forms: Typically in low- to medium-grade regionally metamorphosed igneous and sedimentary rocks, as well as in contact metamorphosed calcium-rich sediments; an alteration product of plagioclase feldspars (saussuritization). If you start seeing amphiboles, plagioclase, quartz in float, you are in the right ground. Typical habit: fibrous, massive, prismatic. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Maine, North Carolina. Start trip planning there.
Common questions
How do you identify clinozoisite?+
Where is clinozoisite found?+
Can I find clinozoisite in the United States?+
What rocks look like clinozoisite?+
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Find clinozoisite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
