Varlamoffite is a secondary tin mineral typically occurring as a yellow oxidation product of stannite or cassiterite. It is most commonly found as earthy, powdery masses or thin crusts lining cavities in weathered tin-bearing hydrothermal veins.
Is this varlamoffite?
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 varlamoffite with a known reference. Varlamoffite sits at Mohs 2-3, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Varlamoffite leaves a yellowish streak.
- 3Read the lusterHold the specimen under a strong light. Varlamoffite typically shows a dull luster.
- 4Match the color rangeCompare against the expected color range: yellow, yellowish-brown, pale yellow.
- 5Look at form & habitCrystal system: tetragonal. Typical habit: powdery, earthy masses, coatings.
Often confused with
Varlamoffite vs. its common look-alikes, and how to tell them apart in the field.
How to tell apart: Cassiterite is the harder of the two (Mohs 6-7 vs. 2-3); streak differs, so Varlamoffite leaves yellowish, Cassiterite leaves white; luster reads dull on Varlamoffite and adamantine on Cassiterite.
How to tell apart: Limonite is the harder of the two (Mohs 4-5.5 vs. 2-3); streak differs, so Varlamoffite leaves yellowish, Limonite leaves yellowish-brown; luster reads dull on Varlamoffite and submetallic to earthy on Limonite.
Often found alongside varlamoffite
Minerals reported to co-occur with varlamoffite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- (Sn,Fe)(O,OH)₂
- Mohs hardness
- 2-3
- Density
- 4.0-5.0 g/cm³
- Streak
- Yellowish
- Luster
- Dull
- Transparency
- Opaque
- Crystal system
- Tetragonal
- Crystal habit
- Powdery, Earthy Masses, Coatings
- Cleavage
- None
- Rarity
- Rare
- Uses
- Collector
- Host rock
- Oxidized Tin Ore Deposits
- Typical price
- $20-100 per specimen
Where rockhounds find varlamoffite
Classic worldwide localities
- Republic of the Congo
- Cornwall, UK
- Bolivia
- Russia
Field-hunting tip
Look in oxidized tin ore deposits country, the host setting where varlamoffite typically forms. If you start seeing cassiterite, stannite, goethite in float, you are in the right ground. Field specimens usually show a powdery, earthy masses, coatings habit, so train your eye for that shape before scanning the outcrop.
Common questions
How do you identify varlamoffite?+
Where is varlamoffite found?+
How much is varlamoffite worth?+
What rocks look like varlamoffite?+
What minerals are found with varlamoffite?+
What kind of rock does varlamoffite form in?+
What is varlamoffite used for?+
Find varlamoffite on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
