Pearls, opals, tanzanite and more
Popular gems at a glance: pearls, opals, tanzanite, aquamarine, amethyst, garnet and spinel.
Typical UK second-hand price
From under £50 (amethyst) to thousands (fine black opal, natural pearls)
Quick guide
- Pearls — natural, cultured (Akoya, South Sea, Tahitian, freshwater). Lustre is key; natural pearls need a lab report.
- Opal — Australian black opal is most valuable; doublets and triplets are layered and worth less.
- Tanzanite — blue-violet, soft (6.5 Mohs); avoid daily-wear rings.
- Aquamarine — pale to deep blue; deeper 'Santa Maria' colour is prized.
- Spinel — durable and increasingly collected, especially red and cobalt blue.
- Garnet, amethyst, citrine, peridot, topaz — affordable, widely available.
Before you buy
- Ask whether opals are solid, doublet or triplet.
- Have any high-value piece checked by an independent valuer or jeweller before paying. JewelleryTrader does not authenticate items.
Frequently asked questions
How can I tell real pearls?
Rubbed gently against teeth, real pearls feel gritty; fakes feel smooth. A lab X-ray tells natural from cultured.
More coloured gemstones guides
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