Gem

Gems are valuable junk items found when Gathering. They drop from both village nodes and nodes in the world. They have no use other than to be sold to a vendor for gold. The six types of gems are topaz, opal, sapphire, ruby, emerald, and diamond, and there is a set of gems for every 5 levels, as well as level 1 gems. (So the name of the level 25 opal is Lustrous Opal.)

The level of the gem dropped is the same as the gathering node rounded down. I.e. a level 49 node drops level 45 gems. All gems stack up to 100.