coral

Coral

The hard skeleton of red coral branches is naturally matte, but can be polished to a glassy shine. It exhibits a range of warm reddish pink colours from pale pink to deep red; the word coral is also used to name such colours. Owing to its intense and permanent colouration and glossiness, precious coral skeletons have been harvested since antiquity for decorative use. Coral jewellery has been found in ancient Egyptian and prehistoric European burials, and continues to be made to the present day.

Stock sizes: Cabochon only
Round: 1.5mm – 14mm
Oval: 3x2mm – 20x15mm
Pear: 5x3mm – 14x9mm
Marquise: 4x2mm – 14x7mm
Heart: 4mm -10mm
A selection of specimen pieces are available

Chemical Formula: CaCO3, Calcium carbonate – organic
Crystal Structure: (Trigonal) microcrystalline
Colour: White , pink, orange, red, black, gold
Hardness: 3 to 4 on Moh`s scale
Refractive Index: 1.486 to 1.658
Specific Gravity: 2.60 to 2.70
Cleavage: None

Treatments: Coral is commonly enhanced to improve its colour and durability. White coral is bleached. Pink coral is permeated with a colourless wax and orange coral is stabilized with plastic. Black coral is sometimes bleached to create gold coral. Occasionally, red coral is dyed to deepen or uniform its colour. All commonly used forms of coral enhancement are stable.

Care: Coral is very sensitive to acid and heat, ultrasonic and steam cleaning are not recommended. Colour is also known to fade with wear and tear. You can wipe down precious coral using a soft cloth and a mild soap or detergent if needed although this will over time reduce the shine.