Strontioborite is a very rare borate mineral found in evaporite environments. It typically appears as small, colorless to white tabular crystals and is known almost exclusively from the Inder salt dome in Kazakhstan.
Is this strontioborite?
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 strontioborite with a known reference. Strontioborite 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. 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. Typical habit: platy.
Often confused with
Strontioborite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside strontioborite
Minerals reported to co-occur with strontioborite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Sr[B₈O₁₁(OH)₄]
- Mohs hardness
- 3.5
- Density
- 2.40 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Semitransparent
- Crystal system
- Monoclinic
- Crystal habit
- Platy
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- In the insoluble residue from a salt dome
Where rockhounds find strontioborite
Classic worldwide localities
- Chelkar salt dome, Ak-saı̆ Valley, Uralsk district, and in the Inder borate deposit, Kazakhstan
Field-hunting tip
Where it forms: In the insoluble residue from a salt dome. If you start seeing ginorite, boracite, halurgite in float, you are in the right ground. Typical habit: platy. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify strontioborite?+
Where is strontioborite found?+
What rocks look like strontioborite?+
What minerals are found with strontioborite?+
What kind of rock does strontioborite form in?+
What is strontioborite used for?+
Find strontioborite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
