Llanite is a unique and rare porphyritic rhyolite found only in Llano County, Texas. It is highly prized by collectors for its distinctive groundmass featuring star-shaped blue quartz crystals and orange-pink microcline feldspar phenocrysts.
Is this llanite?
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 llanite with a known reference. Llanite sits at Mohs 6-7, softer than the next harder reference, harder than the previous one.
- 2Check the streakDrag the specimen across an unglazed porcelain plate. Llanite leaves a white streak.
- 3Read the lusterHold the specimen under a strong light. Llanite typically shows a vitreous luster.
- 4Match the color rangeCompare against the expected color range: brown, reddish-brown, gray, blue.
- 5Look at form & habitTypical habit: massive.
Often confused with
Llanite vs. its common look-alikes, and how to tell them apart in the field.
Often found alongside llanite
Minerals reported to co-occur with llanite. Spotting these in float or country rock is a strong cue you are in the right ground.
All properties
- Mohs hardness
- 6-7
- Density
- 2.6-2.7 g/cm³
- Streak
- White
- Luster
- Vitreous
- Transparency
- Opaque
- Crystal habit
- Massive
- Cleavage
- None
- Rarity
- Rare
- Uses
- Lapidary, Collector, Decorative
- Host rock
- Igneous Rhyolite Dikes
- Typical price
- $10-50 for small polished pieces, $50-200 for larger specimens
Where rockhounds find llanite
1 mapped spotsClassic worldwide localities
- Llano County, Texas, USA
Field-hunting tip
Look in igneous rhyolite dikes country, the host setting where llanite typically forms. If you start seeing quartz, feldspar, fluorite 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 Texas. Start trip planning there.




