Grading lamps are cold — around 6500K, close to overcast daylight. Almost nowhere you will actually wear jewellery is lit that way. Restaurant light is warm. Temple light is warmer still and mostly comes from below. Wedding videography light is brutal and blue.
Warm light suppresses blue and lifts red and yellow. A cornflower sapphire that sings under a grading lamp can go quietly grey across a candlelit table. A ruby does the opposite: it gains. Emerald sits in the middle and depends almost entirely on how much yellow is in the stone to begin with.
A practical test
Ask to see a stone away from the counter lamp, near the shopfront, in daylight — and then ask for the lamp to be switched off entirely. Any jeweller confident in a stone will do both without hesitation. Ten seconds of that will tell you more than a certificate about how the piece will look on the night you actually bought it for.
Matching a set
When stones are matched across a necklace, earrings and a ring, they should be matched in a single session under a single light source. Stones sourced months apart and matched from memory never quite agree, and the disagreement always shows up in photographs rather than in the mirror.
Written at the bench at Sita Shree Jewellers, New Road, Kathmandu. Bring any piece — ours or not — and we will look at it with you across the counter.
