With the Diamond Apple, you could customize your horse's coat. You could choose from among various colors and marks, allowing your horse to have an uncommon coat. It costed 2 passes in the Black Market.
This item was removed due to many errors. Players were having difficulties creating the coats, and certain browsers did not support the feature.
To this day, horses with the Diamond Apple still exist on the game. They can be found in the sales but cost numerous amounts of equus and passes, often going for millions of equus along with dozens of passes. They have become very rare and hard to find.
This item is no longer available for purchase in the Black Market.