Hydroxyledgrewite is a rare calcium-rich garnet species characterized by its significant hydroxyl content. It typically forms in contact metamorphic skarn zones where limestone has reacted with intrusive igneous fluids. Collectors identify it by its close association with other calc-silicate minerals and its distinct, albeit subtle, cubic crystal forms.
Is this hydroxyledgrewite?
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 hydroxyledgrewite with a known reference. Hydroxyledgrewite sits at Mohs 5.5, 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.
- 5Look at form & habitCrystal system: monoclinic.
Often confused with
Hydroxyledgrewite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside hydroxyledgrewite
Minerals reported to co-occur with hydroxyledgrewite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₉(SiO₄)₄(OH)₂
- Mohs hardness
- 5.5
- Density
- 2.916 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Cleavage
- Good on {010}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In xenoliths of carbonate-silicate rock altered to sanidinite facies metamorphic rock within ignimbrites
Where rockhounds find hydroxyledgrewite
Classic worldwide localities
- Upper Chegem caldera, Kabardino-Balkaria, Northern Caucasus, Russia
Field-hunting tip
Where it forms: In xenoliths of carbonate-silicate rock altered to sanidinite facies metamorphic rock within ignimbrites. If you start seeing bultfonteinite, hillebrandite, jennite in float, you are in the right ground.
Common questions
How do you identify hydroxyledgrewite?+
Where is hydroxyledgrewite found?+
What rocks look like hydroxyledgrewite?+
What minerals are found with hydroxyledgrewite?+
What kind of rock does hydroxyledgrewite form in?+
What is hydroxyledgrewite used for?+
Find hydroxyledgrewite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
