A case in point was the stunning sea sediment jasper pendant (see photo) I have just listed on Etsy. The main close-up photo I took of Sea Jasper was one of my better quality photos. It’s far from perfect but it for an untrained photographer with a point and shoot camera it’s not bad. Yet, it just doesn’t convey the lovely soft sheen of the cabochon or capture the translucence you see in real life. Trying to describe the cabochon for listing on Etsy I realised just how limited my vocabulary is for describing gemstone surfaces.
This has begun to niggle at me and since listing the Sea Jasper necklace I’ve done some homework. I found some delightful words used by words used by those gemmologists to describe the surface of sea sediment jasper – it is transparent, translucid, luminescent and fluorescent. Fire agate, the centre of a piece I am working on at present is described on one gemmology site as iridescent. I now realise that it the gemmology language of ‘lustre’ I’m lacking. Lustre is the sheen, shine, patina or gleam of a surface, such as a gemstone. The language of lustre is full of wonderful adjectives – glow, glimmer, sparkle, glitter, twinkle, glisten and shimmer to name a few.
In gemmology lustre refers to the radiance and gloss of a gemstones surface that is created by light reflecting from it and there is a well-recognised language for describing the lustre of different gemstones. For instance:
- Adamanite lustre: diamonds, zircon and rutile
- Metallic lustre: hematite
- Resinous lustre: amber
- Greasy lustre: serpentine
- Waxy lustre: turquoise
- Pearly lustre: rhodinte
- Silky lustre: tiger’s eye
- Opalescent: opals
Whilst, greasy and resinous lustres might not instantly conjure up images of beauty and style, and very few people might know what an adamanite lustre is, I will add ‘silky’ and ‘pearly’ to my newly acquired lustre list.
My homework has given me 15 new words to help me try to speak for gemstones I use: