Alternative Names: When concentrically banded it is called by the sub-variety name Agate. When it is in flat layers/bands it is called by the sub-variety name Onyx. Many other sub-variety names exist, including Jasper, Chrysoprase, Flint etc.

Mineral Information

Origin: Worldwide

Mineral Species: Quartz

Mineral Group: Oxides

Chemical Formula: SiO2

Hardness: 7

Crystal System: Trigonal

Colour: Usually colourless, white, grey or blue, but most colours exist due to other embedded minerals.

Typical Appearance: Traditionally defined as a fibrous cryptocrystalline variety of Quartz. When it is concentrically banded, it is called by the name Agate. When it is in flat layers or bands it is called Onyx.

Esoteric Information

Birthstone: Elemental birthstone of Cancer & Sagittarius

Chakra Alignment: Throat, Third Eye and Bindu Visarga

Element: Air, water

Origin of Name & Mythology: Mentioned by Agricola (1546) of a stone named for the town of Chalcedon, now called Kadikoy, and is a district within the city of Istanbul, Turkey.

Properties: The properties of chalcedony tend to be related to colour and formation. Please click on some chalcedony varities below.

Blue Chalcedony

Green Chalcedony - Chrysoprase

Chalcedony - Nodular ('Womb Balls')

Chalcedony - Stalactitic