Diamonds can only be used in the Diamond Shop to purchase prizes. Most Diamond Items are members only, although AJHQ has put some non-member items in there too. Members can use Diamonds to purchase past Monthly Member Gifts, along with seasonal pets and gift card animals.
Diamonds are given out in Decemeber as part of the Jamaalidays. Also during December, you can buy holiday themed items given out by the "Advent Calander" during the real time of Advent (Dec 1-24)
AJHQ (Animal Jam Headquarters) has confirmed that all Diamond reward rumors to be false, as said in this.
However there has been a Diamond code which grants you one Diamond, as of 2014; twelve.
- You will often see Jammers dressing up in white and dancing on a Diamond in the Diamond shop, claming they have used this method and that it gives Diamonds. Don't waste your time. The only ways to get Diamonds are from the Daily Spin, from codes obtainable at Jamaa Outfitters, and gained by members once a week. Like said above, using twelve in the code widget when logging in gives 1 Diamond. Otherwise, there are no other ways of getting these.