Aleksandrovite is an extremely rare phyllosilicate mineral discovered in the Sakha Republic of Russia. It typically occurs as small tabular crystals within contact-metamorphosed limestone xenoliths. Due to its scarcity, it is almost exclusively found in advanced research collections.
Is this aleksandrovite?
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 aleksandrovite with a known reference. Aleksandrovite sits at Mohs 4-5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Aleksandrovite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Aleksandrovite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: colorless, white.
- 5Look at form & habitCrystal system: trigonal. Typical habit: tabular crystals.
Often confused with
Aleksandrovite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside aleksandrovite
Minerals reported to co-occur with aleksandrovite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- KCa₄(Si₄O₁₀)F
- Mohs hardness
- 4-5
- Density
- 2.81 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Transparent
- Crystal system
- Trigonal
- Crystal habit
- Tabular Crystals
- Cleavage
- Good
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Metamorphic Rocks
Where rockhounds find aleksandrovite
Classic worldwide localities
- Sakha Republic, Russia
Field-hunting tip
Look in metamorphic rocks country, the host setting where aleksandrovite typically forms. If you start seeing spurrite, cuspidine, larnite 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.
Common questions
How do you identify aleksandrovite?+
Where is aleksandrovite found?+
What rocks look like aleksandrovite?+
What minerals are found with aleksandrovite?+
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What is aleksandrovite used for?+
Find aleksandrovite on the map
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