Sugakiite is a rare copper-iron sulfide mineral typically found in intimate intergrowths within skarn-type ore deposits. It is primarily identified in polished sections via microscopic examination due to its extremely small grain size and similarity to other copper-iron sulfides.
Is this sugakiite?
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 sugakiite with a known reference. Sugakiite sits at Mohs 3.5-4, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Sugakiite leaves a black streak.
- 3Read the lusterHold the specimen under a strong light. Sugakiite typically shows a metallic luster.
- 4Match the color rangeCompare against the expected color range: bronze, yellow.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: granular, anhedral.
Often confused with
Sugakiite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Streak differs, so Sugakiite leaves black, Chalcopyrite leaves greenish-black.
How to tell apart: Streak differs, so Sugakiite leaves black, Pentlandite leaves light bronze-brown.
Often found alongside sugakiite
Minerals reported to co-occur with sugakiite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- CuFe₉S₈
- Mohs hardness
- 3.5-4
- Density
- 4.35 g/cm³
- Streak
- Black
- Luster
- Metallic
- Transparency
- Opaque
- Crystal system
- Tetragonal
- Crystal habit
- Granular, Anhedral
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Skarn Deposits
Where rockhounds find sugakiite
Classic worldwide localities
- Akagane mine, Iwate Prefecture, Japan
Field-hunting tip
Look in skarn deposits country, the host setting where sugakiite typically forms. If you start seeing chalcopyrite, pyrrhotite, cubanite in float, you are in the right ground. Field specimens usually show a granular, anhedral habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify sugakiite?+
Where is sugakiite found?+
What rocks look like sugakiite?+
What minerals are found with sugakiite?+
What kind of rock does sugakiite form in?+
What is sugakiite used for?+
Find sugakiite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
