On their quest for the magic lamp with Aladdin, they had entered the cave of wonders, and just like dragons who have their lust of treasure, Rarity and Abu zoomed passed their friends and were about to help themselves, and would’ve too if their friends didn’t pause them just like that. Besides, who ever created this cave and stashed up all of this loot, must’ve used this as a warning, so Rarity and Abu can’t touch anything in the cave.
 
To be fair though, Rarity uses gems and whatnot for her designs. Abu just likes shiny things.
 
Rarity: (Excited like a greedy dragon) Sweet Celestia! Look at all this treasure, gold and diamonds! I must have it for my designs!
 
Abu: Chirps (not before I get it first!)
 
Rarity and Abu: IT MIIINE!