Amethyst geodes are hollow volcanic rocks lined with purple quartz crystals. They are formed within gas bubbles in basaltic lava where silica-rich fluids slowly deposit crystals over millennia.
Is this amethyst geode?
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 amethyst geode with a known reference. Amethyst Geode sits at Mohs 7, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Amethyst Geode leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Amethyst Geode typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: purple, violet.
- 5Look at form & habitCrystal system: trigonal. Typical habit: drusy crystals lining a cavity.
Often confused with
Amethyst Geode vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside amethyst geode
Minerals reported to co-occur with amethyst geode. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- SiO₂
- Mohs hardness
- 7
- Density
- 2.65 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Trigonal
- Crystal habit
- Drusy Crystals Lining A Cavity
- Cleavage
- None
- Rarity
- Common
- Uses
- Collector, Decorative, Lapidary
- Host rock
- Basaltic Volcanic Rock
- Typical price
- $20-200 small cabinet, $500-5000+ large cathedral
Where rockhounds find amethyst geode
2 mapped spotsClassic worldwide localities
- Artigas, Uruguay
- Rio Grande do Sul, Brazil
- Thunder Bay, Canada
- Maverick County, USA
Field-hunting tip
Look in basaltic volcanic rock country, the host setting where amethyst geode typically forms. If you start seeing goethite, hematite, calcite in float, you are in the right ground. Field specimens usually show a drusy crystals lining a cavity habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in California, Colorado. Start trip planning there.
Common questions
How do you identify amethyst geode?+
Where is amethyst geode found?+
Can I find amethyst geode in the United States?+
How much is amethyst geode worth?+
What rocks look like amethyst geode?+
What minerals are found with amethyst geode?+
What kind of rock does amethyst geode form in?+
What is amethyst geode used for?+
Find amethyst geode on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
