Two gemstones.
Side by side.

GEMSTONE ONE

Colemanite

Colemanite guide: identity, composition CaB₃O₄(OH)₃·H₂O, hardness 4.5, origins, collecting and care.

Colour & appearance

Colourless to white, yellowish or grey

Mineral family

hydrated calcium borate mineral

Mohs hardness

4.5

Representative source regions

United States; Turkey; Argentina; Chile

United States Turkey Argentina Chile

Jewellery & care

Colemanite is suited to labelled mineral collections, not jewellery that will experience daily abrasion or water exposure.

ColourlessWhiteGrey

Read the Colemanite guide

GEMSTONE TWO

Sapphire

Sapphire is a gem variety of corundum, often associated with blue but also found in other colours. Its hardness makes it an enduring jewellery material, although the secu...

Colour & appearance

Blue and other colours

Mineral family

Corundum (Al₂O₃)

Mohs hardness

9

Representative source regions

Sri Lanka, Madagascar, Myanmar, Australia, Thailand and Montana in the United States are recognised sources. The Kashmir region is historically famous for highly valued blue sapphires.

Sri Lanka Madagascar Myanmar Australia Thailand United States

Jewellery & care

Choose the style and setting to suit the specific stone, treatment information and intended use.

Blue

Read the Sapphire guide

Hardness measures scratch resistance, not breakage. Source regions are educational examples, not claims about the provenance of an individual GEMHOOD product. Images may be digital gemstone illustrations.