Tychite is a rare sulfate-carbonate mineral typically found in complex evaporite lake deposits. Collectors prize it for its sharp, octahedral crystal habit and its occurrence in highly alkaline saline environments alongside other rare carbonates.

Hardness

3.5-4

Mohs

Luster

Vitreous

Streak

White

Transparency

Transparent to translucent

mineralrareFairchildite Group family

Tychite

Hardness: 3.5-4
Luster: Vitreous
Streak: White
Transparency: Transparent to translucent

Is this tychite?

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 tychite with a known reference. Tychite sits at Mohs 3.5-4, 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.
5
Look at form & habit
Crystal system: cubic. Typical habit: crystalline.

Often confused with

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

Often found alongside tychite

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

All properties

Chemical formula: Na₆Mg₂(CO₃)₄(SO₄)
Mohs hardness: 3.5-4
Density: 2.367-2.743 g/cm³
Colors: White Colorless
Streak: White
Luster: Vitreous
Transparency: Transparent to translucent
Crystal system: Cubic
Crystal habit: Crystalline
Cleavage: None
Fluorescence: Cream-white under LW UV
Rarity: Rare
Uses: Collector
Host rock: Uncommon in lake-bed evaporite deposits

Where rockhounds find tychite

Classic worldwide localities

Searles Lake, San Bernardino Co., California, USA
Green River Formation, Northern Piceance Creek Basin, Colorado, USA
Lake Katwe, western Uganda

Field-hunting tip

Where it forms: Uncommon in lake-bed evaporite deposits. If you start seeing northupite, gaylussite, thénardite in float, you are in the right ground. Typical habit: crystalline. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify tychite?+

Mohs hardness is 3.5-4. Luster: vitreous. The streak is white. Common colors include white, colorless.

Where is tychite found?+

Notable localities include Searles Lake, San Bernardino Co., California, USA; Green River Formation, Northern Piceance Creek Basin, Colorado, USA; Lake Katwe, western Uganda.

What rocks look like tychite?+

Tychite is most often confused with Northupite. A quick hardness test and a streak check separate the look-alikes faster than color alone.

What minerals are found with tychite?+

Tychite commonly co-occurs with Northupite, Gaylussite, Thénardite, Schairerite, Pirssonite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does tychite form in?+

Where it forms: Uncommon in lake-bed evaporite deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is tychite used for?+

Tychite is used in collector.

Find tychite on the map

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