The Blood Rubies (otherwise referred to as "Earth Rubies" in the Harmony Gold English version) are a type of valuable ruby gems that are located within the bottom of the Land of Gurumes and they are the titular objects featured in the first Dragon Ball animated movie Dragon Ball: Curse of the Blood Rubies. Those rubies are cursed and deteriorate everything around them.
King Gurumes paid Bongo and Raven in these in exchange for gathering the Dragon Balls for him. When Penny made a wish to Shenron to restore the land, all of the blood rubies were removed from the ground which seemed to have been behind all of the corruption.
- the space tyrant Frieza describes Planet Vegeta as looking like a blood ruby, shortly before destroying it. This could possibly mean that this resource can be found on other planets as well.