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.

Hardness

6-7

Mohs

Luster

Vitreous

Transparency

Opaque

igneousrare

Llanite

Also: Que-Sera stone, Rhyolite porphyry

Hardness: 6-7
Luster: Vitreous
Transparency: Opaque

Is this llanite?

5-step field check

Run through these checks against the specimen in your hand. The more boxes tick, the more confident the ID.

1
Test the hardness
Try to scratch llanite with a known reference. Llanite sits at Mohs 6-7, softer than the next harder reference, harder than the previous one.
2
Read the texture
Look at a fresh break with a hand lens. Texture: Porphyritic.
3
Pick out the minerals
Composition: About 35 percent quartz, 28 percent microcline, 28 percent plagioclase and 9 percent biotite, with blue quartz and reddish microcline phenocrysts. Identify the two or three most abundant grains.
4
Read the luster
Hold the specimen under a strong light. Luster: vitreous.
5
Match the color range
Compare against the expected color range: brown, reddish-brown, gray, blue.

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
Colors: Brown Reddish-brown Gray Blue
Luster: Vitreous
Transparency: Opaque
Rarity: Rare
Uses: Lapidary, Collector, Decorative
Host rock: igneous rhyolite dikes
Texture: Porphyritic
Composition: About 35 percent quartz, 28 percent microcline, 28 percent plagioclase and 9 percent biotite, with blue quartz and reddish microcline phenocrysts

Where rockhounds find llanite

2 mapped spots

Classic worldwide localities

Llano County, Texas, USA

Field-hunting tip

Where it forms: igneous rhyolite dikes. If you start seeing quartz, feldspar, fluorite in float, you are in the right ground. In the U.S., the densest reported localities are in Texas. Start trip planning there.

Browse 2 U.S. spots for llanite →

Common questions

How do you identify llanite?+

Mohs hardness is 6-7. Texture: Porphyritic. Composition: About 35 percent quartz, 28 percent microcline, 28 percent plagioclase and 9 percent biotite, with blue quartz and reddish microcline phenocrysts. Luster: vitreous. Common colors include brown, reddish-brown, gray, blue.

Where is llanite found?+

Notable localities include Llano County, Texas, USA.

Can I find llanite in the United States?+

RockHoundR maps 2 llanite rockhounding spots across 1 U.S. states. The top states are Texas.

What rocks look like llanite?+

Llanite is most often confused with Granite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with llanite?+

Llanite commonly co-occurs with quartz, feldspar, fluorite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does llanite form in?+

Where it forms: igneous rhyolite dikes. Working float back to the host body is the standard way to chase a fresh occurrence.

What is llanite used for?+

Llanite is used in lapidary, collector, decorative.

Find llanite on the map

RockHoundR shows mapped rockhounding spots, access rules, and lets you log every find.