Fairfield Agate is a variety of chalcedony renowned for its unique, often landscape-like banded patterns and earth-tone coloration. It is typically found as nodules within volcanic tuff deposits in Utah and is highly prized by lapidary artists for cabochon cutting.
Is this fairfield 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 fairfield agate with a known reference. Fairfield 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. Fairfield Agate leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Fairfield Agate typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: brown, tan, white, black, gray.
- 5Look at form & habitCrystal system: trigonal. Typical habit: nodular.
Often confused with
Fairfield Agate vs. its common look-alikes — and how to tell them apart in the field.
How to tell apart: Luster reads vitreous on Fairfield Agate and waxy on Flint Nodules.
How to tell apart: Luster reads vitreous on Fairfield Agate and waxy on Jasper.
How to tell apart: Luster reads vitreous on Fairfield Agate and waxy on Chalcedony.
Often found alongside fairfield agate
Minerals reported to co-occur with fairfield 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
- 2.6-2.7 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Nodular
- Cleavage
- None
- Rarity
- Common
- Uses
- Lapidary, Collector
- Host rock
- Sedimentary Volcanic Tuffs
- Typical price
- $5-50 depending on size and patterns
Where rockhounds find fairfield agate
1 mapped spotsClassic worldwide localities
- Fairfield, Utah
- Cedar Mountains, Utah
- Tooele County, Utah
Field-hunting tip
Look in sedimentary volcanic tuffs country — that is the host setting where fairfield agate typically forms. If you start seeing calcite, quartz, goethite in float, you are in the right ground. Field specimens usually show a nodular habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in South Dakota — start trip planning there.
Common questions
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Find fairfield agate on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
