Lawsonite is a characteristic index mineral of the blueschist metamorphic facies, typically forming in subduction zones. Collectors should look for its distinct tabular crystal habits and characteristic blue-tinted appearance within schistose rock matrices.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineraluncommon

Lawsonite

Hardness: 8
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this lawsonite?

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 lawsonite with a known reference. Lawsonite sits at Mohs 8, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Lawsonite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Lawsonite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: colorless, white, bluish-gray, pale blue, gray.
5
Look at form & habit
Crystal system: orthorhombic. Typical habit: tabular, prismatic, or massive aggregates.

Often confused with

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

mineral

Epidote

Mohs 6-7

How to tell apart: Lawsonite is noticeably harder (Mohs 8 vs. 6-7).

How to tell apart: Lawsonite is noticeably harder (Mohs 8 vs. 6-7); luster reads vitreous on Lawsonite and vitreous to pearly on Zoisite.

How to tell apart: Lawsonite is noticeably harder (Mohs 8 vs. 6-6.5).

Compare →

Often found alongside lawsonite

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

All properties

Chemical formula: CaAl₂Si₂O₇(OH)₂·H₂O
Mohs hardness: 8
Density: 3.05-3.12 g/cm³
Colors: Colorless White Bluish-gray Pale Blue Gray
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Orthorhombic
Crystal habit: Tabular, Prismatic, Or Massive Aggregates
Cleavage: Perfect in Two Directions
Rarity: Uncommon
Uses: Collector, Scientific Research
Host rock: Blueschist Facies Metamorphic Rocks
Typical price: $10-100 per specimen

Where rockhounds find lawsonite

Classic worldwide localities

Tiburon Peninsula, California, USA
Corsica, France
Guatemala
New Caledonia
Valais, Switzerland

Field-hunting tip

Look in blueschist facies metamorphic rocks country, the host setting where lawsonite typically forms. If you start seeing glaucophane, pumpellyite, jadeite in float, you are in the right ground. Field specimens usually show a tabular, prismatic, or massive aggregates habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify lawsonite?+

Mohs hardness is 8. It typically shows a vitreous luster. The streak is white. Common colors include colorless, white, bluish-gray, pale blue.

Where is lawsonite found?+

Notable localities include Tiburon Peninsula, California, USA; Corsica, France; Guatemala; New Caledonia; Valais, Switzerland.

How much is lawsonite worth?+

Typical asking prices fall in the range of $10-100 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like lawsonite?+

Lawsonite is most often confused with Epidote, Zoisite, Prehnite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with lawsonite?+

Lawsonite commonly co-occurs with Glaucophane, Pumpellyite, Jadeite, Aragonite, Garnet. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does lawsonite form in?+

Lawsonite typically forms in blueschist facies metamorphic rocks. Working float back to the host body is the standard way to chase a fresh occurrence.

What is lawsonite used for?+

Lawsonite is used in collector, scientific research.

Find lawsonite on the map

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