How do you craft a sapphire amulet on runescape?

Mine ore like coal or mithril, and it will randomly give random gems including sapphires. If you have high enough crafting level, you can cut it with a chisel.

You can also buy from the Grand Exchange and rarely from Gem Stalls.

It can also be dropped from certain monsters.

If your a member you can mine them from Shilo Village, after completing the

'Shilo Village' Quest.