Hexacelsian is a high-temperature polymorph of barium feldspar that crystallizes in the hexagonal system. It is typically found in rare, high-temperature metamorphic environments such as pyrometamorphic zones or combustion metamorphic rocks. Collectors prize it for its rarity compared to the monoclinic variety, Celsian.
Is this hexacelsian?
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 hexacelsian with a known reference. Hexacelsian sits at Mohs 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: colorless.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: tabular crystals.
Often confused with
Hexacelsian vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside hexacelsian
Minerals reported to co-occur with hexacelsian. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- BaAl₂Si₂O₈
- Mohs hardness
- 6
- Density
- 3.305 g/cm³
- Colors
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Hexagonal
- Crystal habit
- Tabular crystals
- Cleavage
- Very good on {0001}
- Rarity
- Rare
- Uses
- Collector, Scientific research
- Host rock
- A common accessory mineral in thin veins of paralava cutting gehlenite-flamite hornfels and formed at > 1100° C from the relatively fast crystallization of residual melt
Where rockhounds find hexacelsian
Classic worldwide localities
- Found at the Gurim Anticline, near Arad, Negev Desert, Israel
Field-hunting tip
Where it forms: A common accessory mineral in thin veins of paralava cutting gehlenite-flamite hornfels and formed at > 1100° C from the relatively fast crystallization of residual melt. If you start seeing gurimite, rankinite, gehlenite in float, you are in the right ground. Typical habit: tabular crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify hexacelsian?+
Where is hexacelsian found?+
What rocks look like hexacelsian?+
What minerals are found with hexacelsian?+
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Find hexacelsian on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
