In creating jewellery, gemstones, coins, or other precious items are often used, and they are typically set into precious metals. Platinum alloys range from 900 (90% pure) to 950 (95% pure). The silver used in jewellery is usually sterling silver, or 92.5% fine silver. In costume jewellery, stainless steel findings are sometimes used.

Rubies may also have thin, intersecting inclusions called silk. Silk can scatter light, brightening the gem’s appearance, and the presence of silk can also show whether a ruby has been previously heat treated, since intense heat will degrade a ruby’s silk.