Description
A colour-change sapphire of 10.372 carats, cut as an antique cushion and set alone at the centre of the ring. In daylight it reads blue. Under incandescent light it turns purple — the same stone, the same facets, a different colour, and the shift happens as you carry it from a window to a lamp. SSEF grades the change as moderate, which in practice means the two colours are clearly distinguishable without either one being lost.
The cut is worth attention. An antique cushion works differently from a modern one: the facets are larger and fewer, arranged to hold colour in broad blocks rather than break it into small flashes. On a stone whose entire interest is colour, that is the correct decision — the eye is given whole fields of blue or purple to read, not a scatter of them.
Two half-moon diamonds flank the sapphire, one on either side, their straight edges set against the cushion so the three stones sit as a single continuous line across the finger. The band is left plain. Nothing is pavé-set, nothing competes: the sapphire is asked to carry the ring on its own, which is the choice a stone of this weight and this behaviour deserves.
The Swiss Gemmological Institute examined the stone in Basel and reported it as natural corundum from Ceylon, with no indications of heating.
