Tennantite
A variety of Tetrahedrite Group
What is Tennantite?
Tennantite is a usually dull, grey- or black-colored mineral that is a minor ore of copper, and evidence suggests that it has been smelted by humans to produce that useful metal since ancient times. First identified by geologists in Cornwall, England, tennantite is named after Smithson Tennant, an English chemist born in the 18th century.
Etymology & Origins
The mineral was first described for an occurrence in Cornwall, England in 1819, where it occurs as small crystals of cubic or dodecahedral form, and was named after the English chemist Smithson Tennant (1761–1815).
Uses & Applications
Tennantite is an important ore and has been used since before the Bronze Age. Smelting this mineral creates copper-arsenic components that were discovered to be harder than pure copper. Some specimens also have silver and can be used as silver ores.
Market Value Factors
Pricing varies for every rock and mineral, so use these universal factors to gauge Tennantite before comparing listings or appraisals.
Size & Weight
Larger, intact specimens usually command higher prices.
Rarity & Demand
Scarce material or popular varieties sell at a premium.
Condition & Finish
Chips, repairs, and heavy wear lower value; clean prep helps.
Treatment & Provenance
Untreated specimens with documented locality are prized.
Tennantite Localities Map
See where Tennantite is found with a localities map, collecting zones, and geology context. Generate a sample map preview below.
Key Characteristics
Characteristics of Tennantite
The arsenic component of tennantite causes the metal smelted from the ore to be harder than that of pure copper, because it is a copper-arsenic alloy.
Composition of Tennantite
It is gray-black, steel-gray, iron-gray or black in color. A closely related mineral, tetrahedrite has antimony substituting for arsenic and the two form a solid solution series. The two have very similar properties and is often difficult to distinguish between tennantite and tetrahedrite. Iron, zinc, and silver substitute up to about 15% for the copper site.
Health & Safety Information
- ⚠️Tennantite dust is toxic because it contains heavy metals Arsenic, Zinc, Copper.
- ⚠️Arsenic, Zinc, Copper
- ⚠️It's advisable to handle tennantite carefully to avoid generating dust and wash hands thoroughly afterward. When cutting or polishing tennantite, wear a dust mask to prevent inhaling heavy metal particles. Store tennantite in a sealed container in a well-ventilated area, away from children and pets. For those involved in crystal healing, never put it in your mouth.
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Quick Facts
Physical Properties
- Color
- Grey-black, steel-gray, iron-gray, black
- Hardness (Mohs)
- 3 - 4.5
- Density
- 4.6 - 4.7 g/cm³
- Streak
- Reddish gray
- Luster
- Metallic
- Crystal System
- Isometric
Chemical Properties
- Chemical Formula
- Cu6[Cu4(Fe, Zn)2]As4S13
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Tennantite FAQs
How do I identify Tennantite?
Tennantite can be identified by its hardness of 3 - 4.5 on the Mohs scale, Grey-black color, Metallic luster, Isometric crystal system. Look for these key characteristics when examining specimens.
What color is Tennantite?
Tennantite typically appears in Grey-black, steel-gray, iron-gray, black. Color can vary depending on impurities and formation conditions.
How hard is Tennantite?
Tennantite has a hardness of 3 - 4.5 on the Mohs scale. This makes it a soft mineral that can be scratched easily.
What is the characteristics of tennantite of Tennantite?
The arsenic component of tennantite causes the metal smelted from the ore to be harder than that of pure copper, because it is a copper-arsenic alloy.
What is the composition of tennantite of Tennantite?
It is gray-black, steel-gray, iron-gray or black in color. A closely related mineral, tetrahedrite has antimony substituting for arsenic and the two form a solid solution series. The two have very similar properties and is often difficult to distinguish between tennantite and tetrahedrite. Iron, zinc, and silver substitute up to about 15% for the copper site.
