A kyanite blade is a distinctive elongated, bladed crystal, usually blue. Kyanite is famous for its anisotropic hardness, being much softer along the length of the blade than across it, which collectors can verify with a careful scratch test.

Hardness

4.5-7

Mohs

Luster

Vitreous

Streak

White

Transparency

Translucent

mineralcommon

Kyanite Blade

Also: Disthene, Rhaeticite

Hardness: 4.5-7
Luster: Vitreous
Streak: White
Transparency: Translucent

Is this kyanite blade?

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 kyanite blade with a known reference. Kyanite Blade sits at Mohs 4.5-7, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Streak: white.
3
Read the luster
Hold the specimen under a strong light. Luster: vitreous.
4
Match the color range
Compare against the expected color range: blue, white, gray, green, black.
5
Look at form & habit
Crystal system: triclinic. Typical habit: bladed, fibrous, radiating.

Often confused with

Kyanite Blade vs. its common look-alikes, and how to tell them apart in the field.

Often found alongside kyanite blade

Minerals reported to co-occur with kyanite blade. Spotting these in float or country rock is a strong cue you are in the right ground.

All properties

Chemical formula: Al₂SiO₅
Mohs hardness: 4.5-7
Density: 3.53-3.65 g/cm³
Colors: Blue White Gray Green Black
Streak: White
Luster: Vitreous
Transparency: Translucent
Crystal system: Triclinic
Crystal habit: Bladed, fibrous, radiating
Cleavage: Perfect
Rarity: Common
Uses: Collector, Industrial, Lapidary
Host rock: metamorphic schists and gneisses

Where rockhounds find kyanite blade

1 mapped spots

Classic worldwide localities

Switzerland
Brazil
USA (North Carolina)
India
Nepal

Field-hunting tip

Where it forms: metamorphic schists and gneisses. If you start seeing garnet, staurolite, quartz in float, you are in the right ground. Typical habit: bladed, fibrous, radiating. Train your eye for that shape before scanning the outcrop. In the U.S., the densest reported localities are in Pennsylvania. Start trip planning there.

Browse 1 U.S. spots for kyanite blade →

More kyanite blade photos

Common questions

How do you identify kyanite blade?+

Mohs hardness is 4.5-7. Luster: vitreous. The streak is white. Common colors include blue, white, gray, green.

Where is kyanite blade found?+

Notable localities include Switzerland; Brazil; USA (North Carolina); India; Nepal.

Can I find kyanite blade in the United States?+

RockHoundR maps 1 kyanite blade rockhounding spots across 1 U.S. states. The top states are Pennsylvania.

What rocks look like kyanite blade?+

Kyanite Blade is most often confused with Tremolite, Actinolite, Sillimanite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with kyanite blade?+

Kyanite Blade commonly co-occurs with Garnet, Staurolite, Quartz, Mica, Corundum. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does kyanite blade form in?+

Where it forms: metamorphic schists and gneisses. Working float back to the host body is the standard way to chase a fresh occurrence.

What is kyanite blade used for?+

Kyanite Blade is used in collector, industrial, lapidary.

Find kyanite blade on the map

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