Louisiana Opal is a common, non-precious variety of opal found primarily as silicified wood or nodules within sedimentary layers. It is typically opaque and earthy in tone, requiring polishing to reveal a waxy luster suitable for cabochons and lapidary work.
Is this louisiana opal?
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 louisiana opal with a known reference. Louisiana Opal sits at Mohs 5.5-6, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Streak: white.
- 3Read the lusterHold the specimen under a strong light. Luster: waxy.
- 4Match the color rangeCompare against the expected color range: brown, tan, gray, white.
- 5Look at form & habitCrystal system: amorphous. Typical habit: massive.
Often confused with
Louisiana Opal vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside louisiana opal
Minerals reported to co-occur with louisiana opal. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- SiO₂·nH₂O
- Mohs hardness
- 5.5-6
- Density
- 1.9-2.2 g/cm³
- Streak
- White
- Luster
- Waxy
- Transparency
- Opaque
- Crystal system
- Amorphous
- Crystal habit
- Massive
- Cleavage
- None
- Rarity
- Uncommon
- Uses
- Lapidary, Collector
- Host rock
- sedimentary formations
Where rockhounds find louisiana opal
1 mapped spotsClassic worldwide localities
- Vernon Parish, Louisiana
- Sabine Parish, Louisiana
Field-hunting tip
Where it forms: sedimentary formations. If you start seeing quartz, sandstone, iron oxides in float, you are in the right ground. Typical habit: massive. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Louisiana. Start trip planning there.
More louisiana opal photos
Common questions
How do you identify louisiana opal?+
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Can I find louisiana opal in the United States?+
What rocks look like louisiana opal?+
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Find louisiana opal on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
