Sard is a translucent, brownish-red variety of chalcedony that is generally darker and more opaque than carnelian. It is often carved into cameos or used in intaglios due to its toughness and uniform color distribution. It is typically found in sedimentary environments or as fillings in cavities within volcanic rocks.
Is this sard?
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 sard with a known reference. Sard 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. Sard leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Sard typically shows a waxy luster.
- 4Match the color rangeCompare against the expected color range: brownish-red, reddish-brown, orange-brown.
- 5Look at form & habitCrystal system: trigonal. Typical habit: massive.
Often confused with
Sard vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside sard
Minerals reported to co-occur with sard. 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
- 2.6-2.65 g/cm³
- Streak
- White
- Luster
- Waxy
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Massive
- Cleavage
- None
- Rarity
- Common
- Uses
- Gemstone, Lapidary, Ornamental
- Host rock
- Hydrothermal Veins and Cavities
- Typical price
- $5-50 for cabochons or small carvings
Where rockhounds find sard
1 mapped spotsClassic worldwide localities
- India
- Brazil
- Germany
- Uruguay
- Madagascar
Field-hunting tip
Look in hydrothermal veins and cavities country — that is the host setting where sard typically forms. If you start seeing chalcedony, agate, quartz 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 New Jersey — start trip planning there.
Common questions
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Find sard on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
