Steklite is an extremely rare potassium aluminum sulfate mineral found primarily in fumarolic deposits. It is known to occur as thin, transparent, tabular crystals associated with other secondary sulfate minerals at active volcanic sites.
Is this steklite?
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 steklite with a known reference. Steklite sits at Mohs 2.5, 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, white, grayish-white in aggregates.
- 5Look at form & habitCrystal system: trigonal. Typical habit: tabular crystals.
Often confused with
Steklite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside steklite
Minerals reported to co-occur with steklite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- KAl(SO₄)₂
- Mohs hardness
- 2.5
- Density
- 2.797 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Trigonal
- Crystal habit
- Tabular crystals
- Cleavage
- Perfect on {001}
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A volcanic sublimate formed at 150-170 °C as part of sulfate crusts around an active fumarole
Where rockhounds find steklite
Classic worldwide localities
- Burning anthracite coal deposits Eastern Pennsylvania, USA
- Second scoria cone of the Northern Breakthrough of the Great Tolbachik Fissure Eruption (1975–1976), Tolbachik volcano, Kamchatka, and the dumps of coal mine N 47 near Kopeisk, South Urals, Russia
- Showashinzan volcano, Hokkaido, Japan
- Izalco volcano, El Salvador and Santiaguit volcano, Guatemala
Field-hunting tip
Where it forms: A volcanic sublimate formed at 150-170 °C as part of sulfate crusts around an active fumarole. If you start seeing alumoklyuchevskite, langbeinite, euchlorine 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 steklite?+
Where is steklite found?+
What rocks look like steklite?+
What minerals are found with steklite?+
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What is steklite used for?+
Find steklite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
