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
43 mapped spotsClassic worldwide localities
- India
- USA
- Brazil
- Russia
- China
U.S. states with moss agate
Each link opens a state-specific list of mapped rockhounding spots that produce moss agate.
Field-hunting tip
Look in volcanic or sedimentary rocks country, 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 Oregon, Kansas, Wyoming. Start trip planning there.
Common questions
How do you identify moss agate?+
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Find moss agate on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
