The Rainbow Stone is a resource in Black Desert Online.
Overview[edit]
Rainbow stones give you rough topaz, rubys, emeralds, sapphires, and diamonds. Your gathering skill might have to be Skilled1+, if that doesn't work you will for sure be able to get these at Skilled5+. These gemstones can be used to make jewelry, furniture, and socket-able gems.
They are also truly, truly, truly outrageous.
Note: To give credit where credit is due, the map and screenshots below were compiled by AppleTinker. I put it here in the wiki so that it can benefit all players.