Howlite is a borate mineral most commonly found in massive, chalk-white nodules with dark gray veining that creates a spider-web pattern. Because it is porous, it is frequently dyed blue or green to imitate turquoise, often sold as 'Turquenite' or 'White Buffalo' stone.

Hardness

3.5

Mohs

Luster

Subvitreous, glimmering

Streak

White

Transparency

Translucent in thin fragments

mineralcommon

Howlite

Also: White Buffalo, Turquenite

Hardness: 3.5
Luster: Subvitreous, glimmering
Streak: White
Transparency: Translucent in thin fragments

Is this howlite?

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 howlite with a known reference. Howlite sits at Mohs 3.5, 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: subvitreous, glimmering.
4
Match the color range
Compare against the expected color range: white, colorless.
5
Look at form & habit
Crystal system: monoclinic. Typical habit: earthy, massive, nodular.

Often confused with

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

mineral

Magnesite

Mohs 3.5-4.5

How to tell apart: Luster reads subvitreous, glimmering on Howlite and vitreous on Magnesite.

Compare →

Often found alongside howlite

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

All properties

Chemical formula: Ca₂B₅SiO₉(OH)₅
Mohs hardness: 3.5
Density: 2.53-2.59 g/cm³
Colors: White Colorless
Streak: White
Luster: Subvitreous, glimmering
Transparency: Translucent in thin fragments
Crystal system: Monoclinic
Crystal habit: Earthy, massive, nodular
Cleavage: None
Fluorescence: Bright sky blue under LW UV
Rarity: Common
Uses: Lapidary, Collector, Decorative
Host rock: In borate deposits

Where rockhounds find howlite

Classic worldwide localities

Sterling Borax mine, Tick Canyon, near Lang, Los Angeles Co., California, USA
Calico, San Bernardino Co., California, USA
Gower Gulch and at the Billie mine, near Ryan, Inyo Co., California, USA
Russell and other borate mines north of Lockwood Valley, Ventura Co., California, USA
Windsor, Canada
Wentworth, Canada

Field-hunting tip

Where it forms: In borate deposits. If you start seeing colemanite, ulexite, bakerite in float, you are in the right ground. Typical habit: earthy, massive, nodular. Train your eye for that shape before scanning the outcrop.

Common questions

How do you identify howlite?+

Mohs hardness is 3.5. Luster: subvitreous, glimmering. The streak is white. Common colors include white, colorless.

Where is howlite found?+

Notable localities include Sterling Borax mine, Tick Canyon, near Lang, Los Angeles Co., California, USA; Calico, San Bernardino Co., California, USA; Gower Gulch and at the Billie mine, near Ryan, Inyo Co., California, USA; Russell and other borate mines north of Lockwood Valley, Ventura Co., California, USA; Windsor, Canada.

What rocks look like howlite?+

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

What minerals are found with howlite?+

Howlite commonly co-occurs with Colemanite, Ulexite, Bakerite. Spotting any of these in float or country rock is a useful trip signal.

What kind of rock does howlite form in?+

Where it forms: In borate deposits. Working float back to the host body is the standard way to chase a fresh occurrence.

What is howlite used for?+

Howlite is used in lapidary, collector, decorative.

Find howlite on the map

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