Petalite is a lithium-rich silicate mineral primarily found in lithium-bearing pegmatites. It is sought after by collectors for its transparent, gem-quality crystals, though it is often brittle and requires care when handled or faceted.

Hardness

6-6.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineraluncommon

Petalite

Also: Castorite

Hardness: 6-6.5
Luster: Vitreous
Streak: White
Transparency: Transparent

Is this petalite?

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 petalite with a known reference. Petalite sits at Mohs 6-6.5, softer than the next harder reference, harder than the previous one.
2
Check the streak
Drag the specimen across an unglazed porcelain plate. Petalite leaves a white streak.
3
Read the luster
Hold the specimen under a strong light. Petalite typically shows a vitreous luster.
4
Match the color range
Compare against the expected color range: colorless, white, gray, yellow, pink.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: tabular crystals, massive, columnar.

Often confused with

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

Often found alongside petalite

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

All properties

Chemical formula: LiAlSi₄O₁₀
Mohs hardness: 6-6.5
Density: 2.3-2.5 g/cm³
Colors: Colorless White Gray Yellow Pink
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Tabular Crystals, Massive, Columnar
Cleavage: Perfect Basal
Fluorescence: Occasionally Orange or Blue Under UV
Rarity: Uncommon
Uses: Gemstone, Collector, Industrial Source of Lithium
Host rock: Granite Pegmatites
Typical price: $10-50 per gram for gem quality

Where rockhounds find petalite

Classic worldwide localities

Uto, Sweden
Bikita, Zimbabwe
Tanco Mine, Canada
Karibib, Namibia
Newry, Maine, USA

Field-hunting tip

Look in granite pegmatites country, the host setting where petalite typically forms. If you start seeing spodumene, lepidolite, tourmaline in float, you are in the right ground. Field specimens usually show a tabular crystals, massive, columnar habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify petalite?+

Mohs hardness is 6-6.5. It typically shows a vitreous luster. The streak is white. Common colors include colorless, white, gray, yellow.

Where is petalite found?+

Notable localities include Uto, Sweden; Bikita, Zimbabwe; Tanco Mine, Canada; Karibib, Namibia; Newry, Maine, USA.

How much is petalite worth?+

Typical asking prices fall in the range of $10-50 per gram for gem quality. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like petalite?+

Petalite is most often confused with Spodumene, Danburite, Quartz. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with petalite?+

Petalite commonly co-occurs with Spodumene, Lepidolite, Tourmaline, Quartz, Microcline. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does petalite form in?+

Petalite typically forms in granite pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is petalite used for?+

Petalite is used in gemstone, collector, industrial source of lithium.

Find petalite on the map

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