Vivid colours

These Natural Australian opal 26/22mm stones weigh 19.5ct 3.9g. Opal is an amorphous rock, lacking a crystalline structure. There are three basic types of precious opal: boulder opal, black opal and white opal. Black and White Opal have distinct healing properties of their own. There are also other types of Opal, including Fire Opal from Mexico, Green Opal from Madagascar and Pink Opal from Australia.

In Australia, Boulder Opal is mined in Queensland. Black Opal is the most precious and rare form. It is found only at Lightning Ridge, NSW.

Opal is formed when silicic acid gel loses its water and solidifies. Tiny silicon dioxide globules are formed in with a small amount of water and gas enclosed. These globules bend light, giving the opal its wonderful play of colour. The flashing colours are called fire or opalescence. The fire appears as sparkles of vivid colours floating on top of the stone.

Colour: black, blue, green, pink, red, white; iridescent or pearly

Transparency: opaque, translucent, transparent

Lustre: vitreous, waxy

Crystal system: amorphous

Fracture: uneven

Hardness: 5.5-6.5

Mineral group: silicates

Formula: SiO₂·nH₂O

Location: Australia (97 per cent) Ethiopia, Madagascar, Mexico, USA

Rarity: rare, extremely rare

Chakra: Throat, Crown

Emotional: amplifies, awareness, desire, eroticism, release inhibitions, seduction, sexuality, soothing

Mental/intellectual: amplifies, love of life, optimism, spontaneity, unconventional thinking

Spiritual: angelic beings, chakra rebalancing, creativity, inspiration, protection, purification. Brings forth the muse.

Astrology: Libra

Number: 8; Pink Opal, 6; Black Opal, 1

Birthstone: October