Tamarugite is a rare sodium aluminum sulfate mineral typically found as a secondary mineral in arid evaporite settings. Collectors look for its characteristic white to colorless tabular crystals or efflorescent crusts primarily in desert environments like those in Northern Chile.

Hardness

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent

mineralrare

Tamarugite

Hardness: 2
Luster: Vitreous
Streak: White
Transparency: Transparent

No image

Is this tamarugite?

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

Often confused with

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

How to tell apart: Luster reads vitreous on Tamarugite and silky on Pickeringite.

Compare →

Often found alongside tamarugite

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

All properties

Chemical formula: NaAl(SO₄)₂·6H₂O
Mohs hardness: 2
Density: 2.09 g/cm³
Colors: White Colorless
Streak: White
Luster: Vitreous
Transparency: Transparent
Crystal system: Monoclinic
Crystal habit: Tabular Crystals, Massive, Crusts
Cleavage: Perfect
Rarity: Rare
Uses: Collector
Host rock: Arid Evaporite Deposits
Typical price: $20-100 per specimen

Where rockhounds find tamarugite

Classic worldwide localities

Chile
United States
China

Field-hunting tip

Look in arid evaporite deposits country — that is the host setting where tamarugite typically forms. If you start seeing halite, glauberite, bloedite in float, you are in the right ground. Field specimens usually show a tabular crystals, massive, crusts habit, so train your eye for that shape before scanning the outcrop.

Common questions

How do you identify tamarugite?+

Mohs hardness is 2. It typically shows a vitreous luster. The streak is white. Common colors include white, colorless.

Where is tamarugite found?+

Notable localities include Chile; United States; China.

How much is tamarugite worth?+

Typical asking prices fall in the range of $20-100 per specimen. Quality, size, and provenance can move individual specimens well outside that range.

What rocks look like tamarugite?+

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

What minerals are found with tamarugite?+

Tamarugite commonly co-occurs with halite, glauberite, bloedite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does tamarugite form in?+

Tamarugite typically forms in arid evaporite deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is tamarugite used for?+

Tamarugite is used in collector.

Find tamarugite on the map

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