Cinnabar is the primary ore of mercury and is easily recognized by its distinct, vibrant scarlet-red color and high density. It typically forms in hydrothermal veins associated with volcanic activity and is frequently found as massive, earthy, or granular crusts rather than well-formed crystals. Collectors should prioritize safety, as the mineral is toxic and can release hazardous mercury vapors if heated or improperly handled.
Is this cinnabar?
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 cinnabar with a known reference. Cinnabar sits at Mohs 2-2.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Cinnabar leaves a scarlet streak.
- 3Read the lusterHold the specimen under a strong light. Cinnabar typically shows a adamantine luster.
- 4Match the color rangeCompare against the expected color range: red, brownish-red, scarlet.
- 5Look at form & habitCrystal system: trigonal. Typical habit: rhombohedral crystals, massive, granular, or earthy.
Often confused with
Cinnabar vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Cinnabar leaves scarlet, Realgar leaves orange-red; luster reads adamantine on Cinnabar and resinous on Realgar.
How to tell apart: Streak differs, so Cinnabar leaves scarlet, Native Copper leaves copper-red; luster reads adamantine on Cinnabar and metallic on Native Copper.
How to tell apart: Iron Ore is the harder of the two (Mohs 5-6.5 vs. 2-2.5); streak differs, so Cinnabar leaves scarlet, Iron Ore leaves reddish-brown to black; luster reads adamantine on Cinnabar and metallic to submetallic on Iron Ore.
Often found alongside cinnabar
Minerals reported to co-occur with cinnabar. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- HgS
- Mohs hardness
- 2-2.5
- Density
- 8.1-8.2 g/cm³
- Colors
- Streak
- Scarlet
- Luster
- Adamantine
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Rhombohedral Crystals, Massive, Granular, Or Earthy
- Cleavage
- Perfect Prismatic
- Rarity
- Uncommon
- Uses
- Collector, Pigment, Ore of Mercury
- Host rock
- Epithermal Hydrothermal Veins, Volcanic Rocks
- Typical price
- $10-150 thumbnail, $200+ cabinet specimen
Where rockhounds find cinnabar
16 mapped spotsClassic worldwide localities
- Almadén, Spain
- Idrija, Slovenia
- Tongren, China
- California, USA
- Huancavelica, Peru
Field-hunting tip
Look in epithermal hydrothermal veins, volcanic rocks country, the host setting where cinnabar typically forms. If you start seeing pyrite, marcasite, stibnite in float, you are in the right ground. Field specimens usually show a rhombohedral crystals, massive, granular, or earthy habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Nevada, Utah, Arkansas. Start trip planning there.
Common questions
How do you identify cinnabar?+
Where is cinnabar found?+
Can I find cinnabar in the United States?+
How much is cinnabar worth?+
Is cinnabar safe to handle?+
What rocks look like cinnabar?+
What minerals are found with cinnabar?+
What kind of rock does cinnabar form in?+
What is cinnabar used for?+
Find cinnabar on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
