Feldspar is the most abundant mineral group in the Earth's crust, found in almost all igneous, metamorphic, and sedimentary rocks. Collectors should look for its characteristic cleavage planes and vitreous luster, which distinguish it from quartz by its slightly lower hardness and flat cleavage surfaces.
Is this feldspar?
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 feldspar with a known reference. Feldspar sits at Mohs 6 — softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Feldspar leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Feldspar typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: white, gray, pink, colorless, yellow, brown.
- 5Look at form & habitCrystal system: triclinic. Typical habit: prismatic crystals, massive, tabular.
Often confused with
Feldspar vs. its common look-alikes — and how to tell them apart in the field.
Often found alongside feldspar
Minerals reported to co-occur with feldspar. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Chemical formula
- KAlSi₃O₈
- Mohs hardness
- 6
- Density
- 2.5-2.8 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Translucent
- Crystal system
- Triclinic
- Crystal habit
- Prismatic Crystals, Massive, Tabular
- Cleavage
- Perfect in Two Directions
- Rarity
- Common
- Uses
- Industrial, Collector, Lapidary
- Host rock
- Igneous and Metamorphic Rocks
- Typical price
- $5-50 for hand specimens
Where rockhounds find feldspar
65 mapped spotsClassic worldwide localities
- Norway
- Canada
- USA
- Brazil
- Madagascar
U.S. states with feldspar
Each link opens a state-specific list of mapped rockhounding spots that produce feldspar.
Field-hunting tip
Look in igneous and metamorphic rocks country — that is the host setting where feldspar typically forms. If you start seeing quartz, mica, amphibole in float, you are in the right ground. Field specimens usually show a prismatic crystals, massive, tabular habit, so train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Maine, North Carolina, Virginia — start trip planning there.
Common questions
How do you identify feldspar?+
Where is feldspar found?+
Can I find feldspar in the United States?+
How much is feldspar worth?+
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Find feldspar on the map
RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.
