Reyerite is a rare phyllosilicate mineral that forms delicate, pearly-lustered platy or foliated aggregates. It is typically found lining cavities in basaltic rocks, often occurring in association with secondary minerals like gyrolite and apophyllite.

Hardness

3.5-4.5

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent to translucent

mineralrare

Reyerite

Hardness: 3.5-4.5
Luster: Vitreous
Streak: White
Transparency: Transparent to translucent

Is this reyerite?

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 reyerite with a known reference. Reyerite sits at Mohs 3.5-4.5, 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: white, colorless, light green.
5
Look at form & habit
Crystal system: trigonal. Typical habit: massive, micaceous, spherical.

Often confused with

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

Often found alongside reyerite

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

All properties

Chemical formula: Na₂Ca₁₄Al₂Si₂₂O₅₈(OH)₈(H₂O)₆
Mohs hardness: 3.5-4.5
Density: 2.51-2.58 g/cm³
Colors: White Colorless Light green
Streak: White
Luster: Vitreous
Transparency: Transparent to translucent
Crystal system: Trigonal
Crystal habit: Massive, micaceous, spherical
Cleavage: Perfect on {0001}, micaceous
Rarity: Rare
Uses: Collector
Host rock: In tu® (Niaqornat, Greenland); in basalt, within the contact aureole of a volcanic plug (Isle of Mull, Scotland); in a low-grade regionally metamorphosed diabase dike (Rawlings quarry, Virginia, USA)

Where rockhounds find reyerite

Classic worldwide localities

Rawlings quarry, south of McKenney, Brunswick Co., Virginia, USA
Niaqornat (Niakornak), Greenland

Field-hunting tip

Where it forms: In tu® (Niaqornat, Greenland); in basalt, within the contact aureole of a volcanic plug (Isle of Mull, Scotland); in a low-grade regionally metamorphosed diabase dike (Rawlings quarry, Virginia, USA). If you start seeing calcite, chlorite, gyrolite in float, you are in the right ground. Typical habit: massive, micaceous, spherical. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify reyerite?+

Mohs hardness is 3.5-4.5. Luster: vitreous. The streak is white. Common colors include white, colorless, light green.

Where is reyerite found?+

Notable localities include Rawlings quarry, south of McKenney, Brunswick Co., Virginia, USA; Niaqornat (Niakornak), Greenland.

What rocks look like reyerite?+

Reyerite is most often confused with Gyrolite, Okenite, Apophyllite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with reyerite?+

Reyerite commonly co-occurs with Calcite, Chlorite, Gyrolite, Analcime, Pectolite, Thomsonite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does reyerite form in?+

Where it forms: In tu® (Niaqornat, Greenland); in basalt, within the contact aureole of a volcanic plug (Isle of Mull, Scotland); in a low-grade regionally metamorphosed diabase dike (Rawlings quarry, Virginia, USA). Working float back to the host body is the standard way to chase a fresh occurrence.

What is reyerite used for?+

Reyerite is used in collector.

Find reyerite on the map

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