Two gemstones.
Side by side.

GEMSTONE ONE

Cornetite

Discover Cornetite, a copper phosphate known for deep-blue copper phosphate crystals. See verified-reference properties and specimen care advice.

Colour & appearance

Deep blue, blue-green and dark bluish-green

Mineral family

Copper phosphate

Mohs hardness

4.5

Representative source regions

L’Étoile du Congo Mine, Lubumbashi, DR Congo (type locality); other copper mineral localities in the Katanga region

DR Congo

Jewellery & care

A specialist cabinet specimen; unsuitable for exposed daily-wear settings.

BlueBlue-greenGreen

Read the Cornetite 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.