Beryllonite is a rare beryllium phosphate mineral typically found as transparent to translucent crystals in granite pegmatites. It is prized by collectors for its luster and clarity, though it is quite fragile due to its perfect cleavage and sensitivity to mechanical stress.

Hardness

5.5-6

Mohs

Luster

Vitreous to adamantine, may be pearly on {010}

Streak

White

Transparency

Transparent to translucent

mineralrare

Beryllonite

Hardness: 5.5-6
Luster: Vitreous to adamantine, may be pearly on {010}
Streak: White
Transparency: Transparent to translucent

Is this beryllonite?

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 beryllonite with a known reference. Beryllonite sits at Mohs 5.5-6, 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 to adamantine, may be pearly on {010}.
4
Match the color range
Compare against the expected color range: colorless, white, light yellow.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: prismatic, tabular, or equant crystals.

Often confused with

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

mineral

Topaz

Mohs 8

How to tell apart: Topaz is the harder of the two (Mohs 8 vs. 5.5-6).

How to tell apart: Danburite is the harder of the two (Mohs 7-7.25 vs. 5.5-6).

How to tell apart: Quartz is the harder of the two (Mohs 7 vs. 5.5-6).

Compare →

Often found alongside beryllonite

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

All properties

Chemical formula: NaBePO₄
Mohs hardness: 5.5-6
Density: 2.77-2.84 g/cm³
Colors: Colorless White Light yellow
Streak: White
Luster: Vitreous to adamantine, may be pearly on {010}
Transparency: Transparent to translucent
Crystal system: Monoclinic
Crystal habit: Prismatic, tabular, or equant crystals
Cleavage: {010}, perfect; {100}, good, interrupted; {101}, indistinct; {001}, in traces
Rarity: Rare
Uses: Collector, Lapidary
Host rock: As a rare secondary mineral in granitic and alkalic pegmatites

Where rockhounds find beryllonite

Classic worldwide localities

Found on Sugarloaf Mountain, near Stoneham, at the Dunton quarry and the Bell Pit, Newry, Oxford Co., Maine, USA
Occurs at Mont Saint-Hilaire, Quebec, Canada
Found at the Viitaniemi pegmatite, Eräjärvi, Finland
Norrö pegmatite, on Rånö Island, Sweden
Meldon aplite, Okehampton, Devonshire, England
Paprock, Laghman Province, Afghanistan

Field-hunting tip

Where it forms: As a rare secondary mineral in granitic and alkalic pegmatites. If you start seeing herderite, triplite, beryl in float, you are in the right ground. Typical habit: prismatic, tabular, or equant crystals. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify beryllonite?+

Mohs hardness is 5.5-6. Luster: vitreous to adamantine, may be pearly on {010}. The streak is white. Common colors include colorless, white, light yellow.

Where is beryllonite found?+

Notable localities include Found on Sugarloaf Mountain, near Stoneham, at the Dunton quarry and the Bell Pit, Newry, Oxford Co., Maine, USA; Occurs at Mont Saint-Hilaire, Quebec, Canada; Found at the Viitaniemi pegmatite, Eräjärvi, Finland; Norrö pegmatite, on Rånö Island, Sweden; Meldon aplite, Okehampton, Devonshire, England.

Is beryllonite safe to handle?+

Beryllonite contains beryllium. Contains beryllium, which is toxic if inhaled as dust or ingested; handle with care and wash hands thoroughly after handling.

What rocks look like beryllonite?+

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

What minerals are found with beryllonite?+

Beryllonite commonly co-occurs with Herderite, Triplite, Beryl, Apatite, Cassiterite, Columbite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does beryllonite form in?+

Where it forms: As a rare secondary mineral in granitic and alkalic pegmatites. Working float back to the host body is the standard way to chase a fresh occurrence.

What is beryllonite used for?+

Beryllonite is used in collector, lapidary.

Find beryllonite on the map

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