4.5ct Tanzanite Cushion

Specifications

Weight ? One carat is 0.2 grams. Larger stones of equal quality are rarer and cost more per carat.

4.5ct

Price per unit ? The total price divided by the weight — the figure dealers compare stones on.

€666.66 per ct

Colour ? The dominant hue. Colour is the single biggest driver of value in a coloured stone.

Blue

Clarity ? How free the stone is of inclusions, from IF (flawless) down through VVS, VS, SI and I1.

VVS

Cut / shape ? The outline and faceting style the rough was cut to.

Cushion

Cut style ? Faceted stones sparkle; cabochons are domed and polished smooth.

Faceted

Origin ? Where the rough was mined. Some origins carry a premium.

Tanzania

Treatment ? Heated to improve colour and clarity. This is a stable, permanent and industry-standard treatment.

Heated