Moss agate is a variety of chalcedony containing inclusions of manganese or iron oxides that form moss-like or dendritic patterns. It does not display the concentric banding typical of many other agates but is highly prized for its unique, landscape-like imagery within the translucent matrix.
Is this moss agate?
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 moss agate with a known reference. Moss Agate sits at Mohs 6.5-7 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Moss Agate leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Moss Agate typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, green, brown, red, yellow.
- 5Look at form & habitCrystal system: trigonal. Typical habit: massive.
Often confused with
Moss Agate vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside moss agate
Minerals reported to co-occur with moss agate. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- SiO₂
- Mohs hardness
- 6.5-7
- Density
- 2.58-2.64 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Massive
- Cleavage
- None
- Rarity
- Common
- Uses
- Lapidary, Collector, Jewelry
- Host rock
- Volcanic or Sedimentary Rocks
- Typical price
- $5-50 for small specimens, high-quality slabs or cabs $20-150
Where rockhounds find moss agate
39 mapped spotsClassic worldwide localities
- India
- USA
- Brazil
- Russia
- China
Field-hunting tip
Look in volcanic or sedimentary rocks country — that is the host setting where moss agate typically forms. If you start seeing quartz, chalcedony, calcite in float, you are in the right ground. Field specimens usually show a massive habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Kansas, Wyoming, Iowa — start trip planning there.
Common questions
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Find moss agate on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
