Opal

Description

Non-crystallized hydrated silicon oxide
General Physical properties: hardness from 5.5 to 6.5 - very low density from 1.98 to 2.20 g/cm3 - refractive index from 1.44 and 1.46 (monorefractive)

- Weight: 5.11 Kt

- Size 14.50 x 11.50 x 6.00 mm

- Cut: oval cabochon

- Color: perfectly transparent mass with strong spots opalescence with undefined contours of color,
above all green and blue but also red (depending on the incidence of light)

- Treatments: none

- Origin: Mexico

- Note: true collectibles rarity