Strontiojoaquinite is an extremely rare member of the joaquinite group primarily found in the unique hydrothermal environments of the Benitoite Gem Mine. It typically forms small, wedge-shaped or tabular brown crystals that are almost exclusively identified through professional analysis due to their strong resemblance to other members of the joaquinite group.
Is this strontiojoaquinite?
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 strontiojoaquinite with a known reference. Strontiojoaquinite sits at Mohs 5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Strontiojoaquinite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Strontiojoaquinite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: yellow, brown, orange-brown.
- 5Look at form & habitCrystal system: monoclinic. Typical habit: tabular crystals, wedge-shaped.
Often found alongside strontiojoaquinite
Minerals reported to co-occur with strontiojoaquinite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- Na₂Ba₄(Sr,Ba)₄Ti₄(SiO₄)₄(Si₂O₇)₂O₈(OH,F)₂·nH₂O
- Mohs hardness
- 5
- Density
- 3.91 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Monoclinic
- Crystal habit
- Tabular Crystals, Wedge-shaped
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Glaucophane Schist
- Typical price
- $100-500 per specimen
Where rockhounds find strontiojoaquinite
Classic worldwide localities
- San Benito County, California, USA
Field-hunting tip
Look in glaucophane schist country, the host setting where strontiojoaquinite typically forms. If you start seeing benitoite, nefedevite, serandite in float, you are in the right ground. Field specimens usually show a tabular crystals, wedge-shaped habit, so train your eye for that shape before scanning the outcrop.



