Back: Gemstone
One of five kinds of gemstones you can get from having the Box of Riches.
There are five rarities of Rubies, Chipped/Flawed/Regular/Flawless/Perfect, corresponding to the five rarities of items in the game. Each rarity has better stats than the previous one. Higher rarities can be found in the shop if you have a Box of Riches, or by combining identical ones in the inventory.
The gemstones have varying effects depending on where they are placed.