Burnsite is a rare potassium cadmium copper selenite that forms dark red anhedral equidimensional grains. It is a very rare fumarolic sublimate. Associated minerals include cotunnite, sofiite and ilinskite. It was first described from Tolbachik fissure volcano, Kamchatka Peninsula, Russia.
Is this burnsite?
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 burnsite with a known reference. Burnsite sits at Mohs 1-1.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: red.
- 3Read the lusterHold the specimen under a strong light. Luster: vitreous.
- 4Match the color rangeCompare against the expected color range: dark red.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: anhedral grains, microscopic crystals.
Often confused with
Burnsite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Cerussite is the harder of the two (Mohs 3-3.5 vs. 1-1.5); streak differs, so Burnsite leaves red, Cerussite leaves white; luster reads vitreous on Burnsite and adamantine, tending toward vitreous, resinous on Cerussite.
How to tell apart: Streak differs, so Burnsite leaves red, Phosgenite leaves white; luster reads vitreous on Burnsite and adamantine on Phosgenite.
Often found alongside burnsite
Minerals reported to co-occur with burnsite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- KCdCu₇O₂(SeO₃)₂Cl₉
- Mohs hardness
- 1-1.5
- Density
- 3.85 g/cm³
- Colors
- Streak
- Red
- Luster
- Vitreous
- Transparency
- Opaque to translucent
- Crystal system
- Hexagonal
- Crystal habit
- Anhedral grains, microscopic crystals
- Cleavage
- On {0001}, good
- Rarity
- Rare
- Uses
- Collector
- Host rock
- A very rare fumarolic sublimate, formed at an estimated 450°C–500°C
Where rockhounds find burnsite
Classic worldwide localities
- Tolbachik fissure volcano, Kamchatka Peninsula, Russia
Field-hunting tip
Where it forms: A very rare fumarolic sublimate, formed at an estimated 450°C–500°C. If you start seeing cotunnite, sofiite, ilinskite in float, you are in the right ground. Typical habit: anhedral grains, microscopic crystals. Train your eye for that shape before scanning the outcrop.
Common questions
How do you identify burnsite?+
Where is burnsite found?+
Is burnsite safe to handle?+
What rocks look like burnsite?+
What minerals are found with burnsite?+
What kind of rock does burnsite form in?+
What is burnsite used for?+
Find burnsite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
