Rhabdoborite-(W) is an exceptionally rare borate mineral found primarily in the contact-metasomatic boron deposits of the Tayozhnoye region in Russia. It typically occurs as small tabular crystals embedded within skarn mineral assemblages alongside magnetite and ludwigite. Collectors prize it for its restricted type locality and complex borate structure.
Is this rhabdoborite-(w)?
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 rhabdoborite-(w) with a known reference. Rhabdoborite-(W) sits at Mohs 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: beige.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: tabular crystals, subparallel aggregates.
Often confused with
Rhabdoborite-(W) vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside rhabdoborite-(w)
Minerals reported to co-occur with rhabdoborite-(w). Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Mg₁₂(W⁶⁺,V⁵⁺)₁.₅O₆{[BO₃]₆₋ₓ[(P,As)O₄]ₓF₂₋ₓ} (x < 1)
- Mohs hardness
- 5-6
- Density
- 3.59 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Hexagonal
- Crystal habit
- Tabular crystals, subparallel aggregates
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A volcanic sublimate or, more probably, formed by the interaction between fumarolic gas and basalt scoria
Where rockhounds find rhabdoborite-(w)
Classic worldwide localities
- Arsenatnaya fumarole, Second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption, Tolbachik volcano, Kamchatka, Russia
Field-hunting tip
Where it forms: A volcanic sublimate or, more probably, formed by the interaction between fumarolic gas and basalt scoria. If you start seeing rhabdoborite-, anhydrite, diopside in float, you are in the right ground. Typical habit: tabular crystals, subparallel aggregates. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify rhabdoborite-(w)?+
Where is rhabdoborite-(w) found?+
Is rhabdoborite-(w) safe to handle?+
What rocks look like rhabdoborite-(w)?+
What minerals are found with rhabdoborite-(w)?+
What kind of rock does rhabdoborite-(w) form in?+
What is rhabdoborite-(w) used for?+
Find rhabdoborite-(w) on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
