7.7mm Silver-Grey Blue Colour Change Sapphire 2.75ct SA70

This mysterious grey blue sapphire comes to life under lights or in daylight. This very large stone measures 7.7mm and weighs an impressive 2.75 carats.

STONE TYPE - Natural sapphire
DIAMETER - 7.7mm
CARAT WEIGHT - 2.75ct
CUT -
SHAPE - Round
COLOUR - (explain what colour change is because I don't understand it which means others don't is it in all lights or different in different lights or like parti, blue in places and grey in others?) no treatment / unheated
PROVENANCE - Madagascar
GEMSTONE CODE - SA70 (please quote this when enquiring about a bespoke ring design)