Brianroulstonite is a rare calcium borate, typically colorless to white. It is a very rare in residues from halite-sylvite evaporites. It was first described from Penobsquis evaporite deposit, near Sussex, New Brunswick, Canada.
Is this brianroulstonite?
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 brianroulstonite with a known reference. Brianroulstonite sits at Mohs 3.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Brianroulstonite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Brianroulstonite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: colorless, white.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: tabular crystals.
Often confused with
Brianroulstonite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside brianroulstonite
Minerals reported to co-occur with brianroulstonite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ca₃B₅O₆(OH)₇Cl₂·8H₂O
- Mohs hardness
- 3.5
- Density
- 1.97 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Tabular Crystals
- Cleavage
- On {010}, Perfect
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Evaporite Deposits
Where rockhounds find brianroulstonite
Classic worldwide localities
- Salt Springs, New Brunswick, Canada
Field-hunting tip
Look in evaporite deposits country, the host setting where brianroulstonite typically forms. If you start seeing boracite, halite, goyazite in float, you are in the right ground. Field specimens usually show a tabular crystals habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify brianroulstonite?+
Where is brianroulstonite found?+
What rocks look like brianroulstonite?+
What minerals are found with brianroulstonite?+
What kind of rock does brianroulstonite form in?+
What is brianroulstonite used for?+
Find brianroulstonite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
