Itsiite is an extremely rare borosilicate mineral discovered in the Itsi Mountains of Yukon, Canada. It typically appears as small, honey-yellow tabular crystals found within skarn deposits associated with boron-rich hydrothermal activity.
Is this itsiite?
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 itsiite with a known reference. Itsiite sits at Mohs 4, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Itsiite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Itsiite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: yellow, brownish-yellow.
- 5Look at form & habitCrystal system: trigonal. Typical habit: tabular crystals.
Often confused with
Itsiite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside itsiite
Minerals reported to co-occur with itsiite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Ba₂CaB₄Si₄O₁₆(OH)₂
- Mohs hardness
- 4
- Density
- 3.31 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Trigonal
- Crystal habit
- Tabular Crystals
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Skarn
- Typical price
- $50-300 per specimen
Where rockhounds find itsiite
Classic worldwide localities
- Itsi Mountains, Yukon, Canada
Field-hunting tip
Look in skarn country, the host setting where itsiite typically forms. If you start seeing gowerite, danburite, fluorite 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.




