Obsidian nodules, often known as Apache Tears, are naturally rounded, pebble-like masses of volcanic glass. They are typically found embedded within softer perlite matrix and are prized by collectors for their smooth, water-worn appearance and conchoidal fracturing.
Is this obsidian nodules?
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 obsidian nodules with a known reference. Obsidian Nodules sits at Mohs 5-5.5, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Obsidian Nodules leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Obsidian Nodules typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: black, brown, gray.
- 5Look at form & habitTypical habit: rounded nodules.
Often confused with
Obsidian Nodules vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside obsidian nodules
Minerals reported to co-occur with obsidian nodules. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Mohs hardness
- 5-5.5
- Density
- 2.4 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal habit
- Rounded Nodules
- Cleavage
- None
- Rarity
- Common
- Uses
- Lapidary, Collector, Decorative
- Host rock
- Rhyolitic Volcanic Ash and Perlite
- Typical price
- $2-20 per nodule
Where rockhounds find obsidian nodules
Classic worldwide localities
- Arizona, USA
- Nevada, USA
- Mexico
- Iceland
Field-hunting tip
Look in rhyolitic volcanic ash and perlite country, the host setting where obsidian nodules typically forms. If you start seeing perlite, rhyolite, quartz in float, you are in the right ground. Field specimens usually show a rounded nodules habit, so train your eye for that shape before scanning the outcrop.
More obsidian nodules photos
Common questions
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Find obsidian nodules on the map
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