Bredigite is an uncommon nesosilicate mineral typically found in high-temperature contact metamorphic environments and artificial slag. It most often occurs as small granular aggregates or massive patches, making it a challenging species for non-specialist collectors to identify without analytical verification.
Is this bredigite?
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 bredigite with a known reference. Bredigite sits at Mohs 5.5-6, 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, gray.
- 5Look at form & habitCrystal system: orthorhombic. Typical habit: granular, massive, rarely distinct crystals.
Often confused with
Bredigite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside bredigite
Minerals reported to co-occur with bredigite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₇Mg(SiO₄)₄
- Mohs hardness
- 5.5-6
- Density
- 3.42 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Orthorhombic
- Crystal habit
- Granular, massive, rarely distinct crystals
- Cleavage
- Distinct on {130}
- Rarity
- Rare
- Uses
- Collector, Scientific research
- Host rock
- In contact metamorphosed limestones and dolostones intruded by diabase (Scawt Hill, Ireland) or syenite monzonite (Marble Canyon, Texas, USA)
Where rockhounds find bredigite
Classic worldwide localities
- Marble Canyon, Culberson Co., Texas, USA
- Scawt Hill and Ballycraigy, near Larne, Co. Antrim, Ireland
- Hatrurim Formation, Israel
Field-hunting tip
Where it forms: In contact metamorphosed limestones and dolostones intruded by diabase (Scawt Hill, Ireland) or syenite monzonite (Marble Canyon, Texas, USA). If you start seeing larnite, spurrite, gehlenite in float, you are in the right ground. Typical habit: granular, massive, rarely distinct crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify bredigite?+
Where is bredigite found?+
What rocks look like bredigite?+
What minerals are found with bredigite?+
What kind of rock does bredigite form in?+
What is bredigite used for?+
Find bredigite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
