Loch Roag, Lewis, Isle of Lewis and Harris, Outer Hebrides (Na h-Eileanan Siar), Scotland, UK

Sapphires were found during road construction after exposure of a monchiquite dike, traced for 25m with a thickness varying from 0.5m to 1.5m.

Sapphire crystals have hexagonal, pyramidal-dipyramidal or bladed habit with an average size of 2 to 3cm. Smaller crystals are pure blue, larger stones are spotty blue and green with occasional yellow patches. The indices of refraction are 1.762 - 1.775 and the density is 3.95 - 4.05 g/cm³ (Jackson, 1984).

Ref: E.Ya. Kievlenko (2003) Geology of gems, p. 48

Gemstone List


Copyright © Jolyon & Katya Ralph 1993-2018. Site Map. Locality, gem & photograph data are the copyright of the individuals who submitted them. For more information please contact the . Gemdat.org is an online information resource dedicated to providing free gemmological information to all.