Spencerite is a rare secondary zinc phosphate mineral typically found in the oxidized zones of zinc-rich ore deposits. It often forms distinctive pearly, platy crystals or foliated masses associated with other zinc minerals like smithsonite.

Hardness

Mohs

Luster

Vitreous, pearly on cleavages

Streak

White

Transparency

Transparent to translucent

mineralrare

Spencerite

Hardness: ~3
Luster: Vitreous, pearly on cleavages
Streak: White
Transparency: Transparent to translucent

Is this spencerite?

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 spencerite with a known reference. Spencerite sits at Mohs ~3, 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, pearly on cleavages.
4
Match the color range
Compare against the expected color range: white.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: radial.

Often confused with

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

Often found alongside spencerite

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

All properties

Chemical formula: Zn₄(PO₄)₂(OH)₂·3H₂O
Mohs hardness: ~3
Density: 3.123-3.145 g/cm³
Colors: White
Streak: White
Luster: Vitreous, pearly on cleavages
Transparency: Transparent to translucent
Crystal system: Monoclinic
Crystal habit: Radial
Cleavage: On {100}, perfect; on {010}, good; on {001}, distinct
Rarity: Rare
Uses: Collector
Host rock: A rare secondary mineral in some zinc-bearing hydrothermal deposits

Where rockhounds find spencerite

Classic worldwide localities

Found in the Hudson Bay mine, about eight km southeast of Salmo, near Nelson, Kootenay district, British Columbia, Canada
Kabwe (Broken Hill), Zambia
Turf Pits mine, Grassington Moor, Yorkshire, England

Field-hunting tip

Where it forms: A rare secondary mineral in some zinc-bearing hydrothermal deposits. If you start seeing hemimorphite, hopeite, smithsonite in float, you are in the right ground. Typical habit: radial. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify spencerite?+

Mohs hardness is ~3. Luster: vitreous, pearly on cleavages. The streak is white. Common colors include white.

Where is spencerite found?+

Notable localities include Found in the Hudson Bay mine, about eight km southeast of Salmo, near Nelson, Kootenay district, British Columbia, Canada; Kabwe (Broken Hill), Zambia; Turf Pits mine, Grassington Moor, Yorkshire, England.

What rocks look like spencerite?+

Spencerite is most often confused with Hopeite, Parahopeite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with spencerite?+

Spencerite commonly co-occurs with Hemimorphite, Hopeite, Smithsonite, Cerussite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does spencerite form in?+

Where it forms: A rare secondary mineral in some zinc-bearing hydrothermal deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is spencerite used for?+

Spencerite is used in collector.

Find spencerite on the map

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