Mattagamite is a rare cobalt telluride mineral that typically appears as metallic, white to gray grains within sulfide ore deposits. It is best identified through microscopic analysis and electron microprobe testing, as it rarely forms distinct macroscopic crystals. It is primarily sought after by advanced mineral collectors of rare telluride species.
Is this mattagamite?
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 mattagamite with a known reference. Mattagamite sits at Mohs 3.5 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Mattagamite leaves a gray streak.
- 3Read the lusterHold the specimen under a strong light. Mattagamite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: white, gray.
- 5Look at form & habitCrystal system: hexagonal. Typical habit: massive, granular.
Often confused with
Mattagamite vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Mattagamite is noticeably harder (Mohs 3.5 vs. 2.5); streak differs — Mattagamite leaves gray, Froodite leaves black.
How to tell apart: Mattagamite is noticeably harder (Mohs 3.5 vs. 1-1.5); streak differs — Mattagamite leaves gray, Melonite leaves black.
How to tell apart: Mattagamite is noticeably harder (Mohs 3.5 vs. 1.5-2); streak differs — Mattagamite leaves gray, Tellurobismuthite leaves lead-gray.
Often found alongside mattagamite
Minerals reported to co-occur with mattagamite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CoTe₂
- Mohs hardness
- 3.5
- Density
- 8.8-9.2 g/cm³
- Streak
- Gray
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Hexagonal
- Crystal habit
- Massive, Granular
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Volcanogenic Massive Sulfide Deposits
- Typical price
- $50-300 thumbnail
Where rockhounds find mattagamite
Classic worldwide localities
- Mattagami Lake mine, Quebec, Canada
- Hope's Nose, Torquay, Devon, England
- Moctezuma mine, Sonora, Mexico
Field-hunting tip
Look in volcanogenic massive sulfide deposits country — that is the host setting where mattagamite typically forms. If you start seeing tellurobismuthite, altaite, chalcopyrite in float, you are in the right ground. Field specimens usually show a massive, granular habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify mattagamite?+
Where is mattagamite found?+
How much is mattagamite worth?+
Is mattagamite safe to handle?+
What rocks look like mattagamite?+
What minerals are found with mattagamite?+
What kind of rock does mattagamite form in?+
What is mattagamite used for?+
Find mattagamite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
