A bi-colour Sapphire gemstone from Sri Lanka.
The eye-clean gem displays a vibrant medium blue colour from most viewing angles but when viewed through the table facet a broad greenish-yellow colour zone can be seen.
The zone has an hexagonal outline, following the crystal habit of the Sapphire crystal.
The feature is best seen when the stone is held against a pale background (see images).
The point where the two colours blend is best seen under magnification, as shown in magnified image 4.
weight: 1.56 carats
shape: Mixed oval cut
dimensions: 8.06 x 6.02 x 3.61 mm
treatment: Heat treated