Wegscheiderite is a rare sodium carbonate mineral typically found in the evaporite deposits of the Green River Formation. It usually occurs as massive to granular aggregates or distinct tabular crystals in association with other rare evaporite species.

Hardness

2.5-3

Mohs

Luster

Vitreous

Streak

White

Transparency

Semitransparent

mineralrare

Wegscheiderite

Hardness: 2.5-3
Luster: Vitreous
Streak: White
Transparency: Semitransparent

Is this wegscheiderite?

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 wegscheiderite with a known reference. Wegscheiderite sits at Mohs 2.5-3, 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.
4
Match the color range
Compare against the expected color range: colorless.
5
Look at form & habit
Crystal system: triclinic. Typical habit: tabular crystals, massive, granular.

Often confused with

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

Often found alongside wegscheiderite

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

All properties

Chemical formula: Na₅(CO₃)(HCO₃)₃
Mohs hardness: 2.5-3
Density: 2.341 g/cm³
Colors: Colorless
Streak: White
Luster: Vitreous
Transparency: Semitransparent
Crystal system: Triclinic
Crystal habit: Tabular crystals, massive, granular
Cleavage: Prismatic, distinct
Rarity: Rare
Uses: Collector
Host rock: As a replacement of trona in a lacustrine deposit

Where rockhounds find wegscheiderite

Classic worldwide localities

Green River Formation, from the Perkins Well No. 1, the Perkins Well No. 2, about 10 km west, and as Grierson Well No. 1, about 20 km northwest, Sweetwater Co., Utah, USA
Piceance Basin, Garfield and Rio Blanco Cos., Colorado, USA
Biyang Basin, Henan Province, China

Field-hunting tip

Where it forms: As a replacement of trona in a lacustrine deposit. If you start seeing trona, halite in float, you are in the right ground. Typical habit: tabular crystals, massive, granular. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify wegscheiderite?+

Mohs hardness is 2.5-3. Luster: vitreous. The streak is white. Common colors include colorless.

Where is wegscheiderite found?+

Notable localities include Green River Formation, from the Perkins Well No. 1, the Perkins Well No. 2, about 10 km west, and as Grierson Well No. 1, about 20 km northwest, Sweetwater Co., Utah, USA; Piceance Basin, Garfield and Rio Blanco Cos., Colorado, USA; Biyang Basin, Henan Province, China.

What rocks look like wegscheiderite?+

Wegscheiderite is most often confused with Trona, Nahcolite, Shortite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with wegscheiderite?+

Wegscheiderite commonly co-occurs with Trona, Halite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does wegscheiderite form in?+

Where it forms: As a replacement of trona in a lacustrine deposit. Working float back to the host body is the standard way to chase a fresh occurrence.

What is wegscheiderite used for?+

Wegscheiderite is used in collector.

Find wegscheiderite on the map

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