Sborgite is a rare hydrous sodium borate mineral found in arid evaporite environments. It typically occurs as white crusts or tiny tabular crystals that dehydrate quickly when removed from their native environment, making them difficult to preserve in dry climates.

Hardness
2
Mohs
Luster
Vitreous
Streak
White
Transparency
Transparent

Is this sborgite?

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 sborgite with a known reference. Sborgite 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. Sborgite leaves a white streak.
  • 3
    Read the luster
    Hold the specimen under a strong light. Sborgite 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, crusts, or efflorescences.

Often confused with

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

Often found alongside sborgite

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

All properties

Chemical formula
Na(B₅O₆(OH)₄)·3H₂O
Mohs hardness
2
Density
1.87 g/cm³
Streak
White
Luster
Vitreous
Transparency
Transparent
Crystal system
Monoclinic
Crystal habit
Tabular Crystals, Crusts, Or Efflorescences
Cleavage
Perfect
Rarity
Rare
Uses
Collector, Scientific Research
Host rock
Evaporite Deposits in Arid Lake Beds
Typical price
$20-100 for small study specimens

Where rockhounds find sborgite

Classic worldwide localities

  • Borax Lake, California
  • Searles Lake, California
  • Salar de Atacama, Chile

Field-hunting tip

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

Common questions

How do you identify sborgite?+
Mohs hardness is 2. It typically shows a vitreous luster. The streak is white. Common colors include white, colorless.
Where is sborgite found?+
Notable localities include Borax Lake, California; Searles Lake, California; Salar de Atacama, Chile.
How much is sborgite worth?+
Typical asking prices fall in the range of $20-100 for small study specimens. Quality, size, and provenance can move individual specimens well outside that range.
What rocks look like sborgite?+
Sborgite is most often confused with Borax, Kernite, Ulexite. A quick hardness test and a streak check separate the look-alikes faster than color alone.
What minerals are found with sborgite?+
Sborgite commonly co-occurs with Borax, Ulexite, Halite, Thenardite. Spotting any of these in float or country rock is a useful trip signal.
What kind of rock does sborgite form in?+
Sborgite typically forms in evaporite deposits in arid lake beds. Working float back to the host body is the standard way to chase a fresh occurrence.
What is sborgite used for?+
Sborgite is used in collector, scientific research.

Find sborgite on the map

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