Mineral

Magnesite or Howlite with Matrix

Magnesium carbonate (MgCO3) or Calcium borosilicate hydroxide (Ca2B5SiO9(OH)5)

Hardness: 3.5-4.5 for Magnesite, 3.5 for Howlite. Color: Naturally white/cream with grey/brown matrix, often dyed. Luster: Dull to earthy. Crystal structure: Trigonal (Magnesite), Monoclinic (Howlite).

Hardness: 3
Color: Naturally white/cream with grey/brown matrix, often dyed
Luster: Dull to earthy

Identified June 17, 2026More mineral →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed in evaporite deposits or through the alteration of magnesium-rich rocks (Magnesite) or in continental evaporite deposits (Howlite).

Uses & applications

Commonly carved into cabochons, beads, and pendants for jewelry. Often dyed to simulate turquoise (turquoise-dyed howlite/magnesite is sometimes called 'turquenite').

Geological facts

Both minerals are highly porous, making them excellent candidates for dyeing, which is why they are frequently used as turquoise substitutes.

Field identification & locations

Identified by its web-like grey or brown matrix against a lighter background. Easily scratched compared to true turquoise.

Other mineral specimens

See all

Sandstone (with potential mineral staining/concretions)

Arenite (SiO2 based)

sedimentary

Schist

Metamorphic

Epidote

Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)

metamorphic

Nephrite Jade

Nephrite

Mineral/Rock

Banded Gneiss (River Rock/Pebble)

Gneiss (specifically a banded variety often found as a river rock)

Metamorphic Rock

Green Apatite on Albite

Fluorapatite [Ca5(PO4)3F] on Albite [Na(AlSi3O8)]

mineral