Hatrurite is an extremely rare calcium silicate mineral primarily known from combustion metamorphic complexes. It forms as a product of high-temperature reactions in carbonate-rich rocks and is chemically analogous to alite found in Portland cement clinker.
Is this hatrurite?
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 hatrurite with a known reference. Hatrurite sits at Mohs 6, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: colorless, brownish red.
- 5Look at form & habitCrystal system: trigonal. Typical habit: equant crystals, granular.
Often confused with
Hatrurite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Hatrurite is noticeably harder (Mohs 6 vs. 3).
How to tell apart: Streak differs, so Hatrurite leaves white, Brownmillerite leaves light brown; luster reads vitreous on Hatrurite and submetallic on Brownmillerite.
Often found alongside hatrurite
Minerals reported to co-occur with hatrurite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₃SiO₅
- Mohs hardness
- 6
- Density
- 3.02 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent to translucent
- Crystal system
- Trigonal
- Crystal habit
- Equant crystals, granular
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector, Scientific research
- Host rock
- In a high-temperature contact metamorphic assemblage in a larnite-brownmillerite-mayenite rock, probably derived from fine-grained sediments
Where rockhounds find hatrurite
Classic worldwide localities
- Hatrurim Formation, Israel
Field-hunting tip
Where it forms: In a high-temperature contact metamorphic assemblage in a larnite-brownmillerite-mayenite rock, probably derived from fine-grained sediments. If you start seeing nagelschmidtite, larnite, brownmillerite in float, you are in the right ground. Typical habit: equant crystals, granular. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify hatrurite?+
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What rocks look like hatrurite?+
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Find hatrurite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
