Crystal Structure
Trigonal HgS.
Elemental Composition (by mass)
| Element | Mass % | Visual |
|---|---|---|
| Hg Mercury | 86.22% | |
| S Sulfur | 13.78% |
Computed from simplified end-member formula. Solid-solution series, water content, and trace substitutions cause real-world variation.
IMA Abbreviation (Whitney-Evans 2010)
Cin
→ Cinnabar
Hg sulfide
Standard symbol from American Mineralogist (Whitney & Evans, 2010). Used in thin-section labeling, phase diagrams, and IMA-style species records.
⏳ Long-term Aging & Care Timeline
surface darkeningyears
Trigger: light + air
Intervention: Bright red may dull. Light limitation extends color life.
Pronunciation
/ˈsɪnəbɑːr/
↔ SIN-uh-bar
Persian zinjifrah
Lapidary & Faceting Recommendations
Recommended cut:
cabochon (rare)
Also seen:
cabochon
Typical yield:
25% of rough
Soft (Mohs 2-2.5); rarely cut. Some Chinese material occasionally cabbed for collector market.
⚠ Safety & Handling
☠toxichigh
Mercury sulfide — Hg released by abrasion, heat, or acid. Cinnabar dust is hazardous.
Handling: Handle whole crystals only. Wash hands after. Never grind or polish. Never heat. Keep away from children.
Information provided in good faith. Consult local hazmat regulations for transport and disposal. Severely hazardous specimens may require special storage cabinets.
Tenacity
Behavior:
sectile
Under stress:
Cuts; cleaves
Soft (Mohs 2-2.5); can be sliced.
Luster
adamantine→sub-metallic
High RI gives near-metallic shine to red surfaces.
Diaphaneity (Transparency)
transparent-to-translucent
Rare gem-grade transparent material from China.
Diagnostic Field Tests
Streak test→ Scarlet red
Diagnostic — separates from realgar (orange-red).
SG check→ ~8.1 g/cm³ — feels very heavy
Among the densest non-metals.
⚠ Use dilute HCl (~10%) only on inconspicuous spots; rinse promptly. Smell-tests should be brief and ventilated. Taste-test ONLY halite/sylvite — never lead, arsenic, or sulfur minerals.
Specific Gravity
8.00–8.20
g/cm³
very heavy
HgS; among the densest non-metal minerals.
For comparison: water = 1.00, glass ≈ 2.5, quartz = 2.65, corundum ≈ 4.00, galena ≈ 7.50, gold ≈ 19.3.
Streak Test
scarlet red
Bright scarlet — distinct from realgar (orange-red).
Streak = color of the powdered mineral. Drag specimen across unglazed white porcelain plate (Mohs 6.5). For minerals harder than the plate, crush a small flake into powder and observe color.
Geological Setting
Environment:
hydrothermal
Host rock:
epithermal vein, hot-spring deposit
Companions:
Low-temperature hydrothermal; Almadén (Spain), Idrija (Slovenia), Wanshan (China).
Care notesStable but handle gloved (Hg). Avoid heating. Full cleaning guide →
Formation eraEpithermal Hg deposit; Spanish Almadén ordovician+ multiple events.
Cleavage & Fracture
Cleavage:
perfect 3 directions {1010} — prismatic
Fracture:
subconchoidal
Easy cleavage; brittle.
Market availability: Rare
Sought after; limited supply. Major shows and specialist dealers only.
Collector tier: Cabinet Classic
World-class display species — sought after for cabinet collections, well-documented localities, frequent show-piece pieces.
PolymorphsShares the formula
HgS with: Metacinnabar — same chemistry, different crystal structure.Mohs 2–2.5
Vickers (~) 75 HV
Knoop (~) 85 HK
Nickel–Strunz
2.CD.15aDana
02.08.14.01Diagnostic properties
Specific gravity > 5 — heavy in the hand">Notably dense
Element composition by mass
Formula: HgS · molar mass: 232.65 g/mol
| Hg | 86.22% | |
| S | 13.78% |
Computed from atomic weights (IUPAC 2021). Site-occupancy groups (Fe,Mn) split equally.
Mohs Hardness
2–2.5
Cinnabar sits at 2–2.5 on the Mohs scale — soft enough to be scratched by a fingernail.
Colors:
Streak
Scarlet
Scarlet
Crystal system
Trigonal
Trigonal
Pronunciation/ˈsɪnəbɑːr/
Type localityAlmadén, Ciudad Real, Spain
Discovery Known since antiquity
Sulfides & SulfosaltsSulfides
TL;DR · 1 min read
Cinnabar (HgS) is the primary ore of mercury and one of the most visually arresting minerals on Earth — its scarlet-to-vermilion crystals have been mined for pigment, alchemy, and metallurgy for over 3,000 years. China is the world's leading historical producer, with Wanshan (Guizhou) and Tongren (Guizhou) supplying both industrial mercury and museum-grade collector specimens.
Cinnabar (HgS) is the primary ore of mercury and one of the most visually arresting minerals on Earth — its scarlet-to-vermilion crystals have been mined for pigment, alchemy, and metallurgy for over 3,000 years. China is the world’s leading historical producer, with Wanshan (Guizhou) and Tongren (Guizhou) supplying both industrial mercury and museum-grade collector specimens.
Notable Chinese Localities
Wanshan Mine (Guizhou) is China’s premier cinnabar source and the type-locality benchmark for sharp rhombohedral crystals on white dolomite matrix. Tongren and Wuchuan (also Guizhou) and Hunan’s Xiangxi belt also produce collector material.
Cite this entry
APA
MyMineralBox Editorial Team. (2026). Cinnabar. My Mineral Box. Retrieved May 23, 2026, from https://mymineralbox.com/mineral-encyclopedia/minerals/cinnabar/
MLA
MyMineralBox Editorial Team. "Cinnabar." My Mineral Box, 2026, https://mymineralbox.com/mineral-encyclopedia/minerals/cinnabar/. Accessed May 23, 2026.
Chicago
MyMineralBox Editorial Team. "Cinnabar." My Mineral Box. Last modified May 4, 2026. https://mymineralbox.com/mineral-encyclopedia/minerals/cinnabar/.
BibTeX
@misc{mmb_cinnabar,
author = {{MyMineralBox Editorial Team}},
title = {{Cinnabar}},
year = {2026},
publisher = {My Mineral Box},
url = {https://mymineralbox.com/mineral-encyclopedia/minerals/cinnabar/},
urldate = {2026-05-23}
}