Just like the Dino Pen where you can combine DNA's to create Dinosaurs, the Unicorn Islands works just the same but with Gems.
Here is a guide of all the Gem combinations to creat the available Unicorns and Pegacorns.
Pink Lemonade Unicorn
| Purple Amethyst x10  |
Moon Unicorn
| Purple Amethyst x12 |
Supernova Unicorn
| Purple Amethyst x6 |
White Diamond x8  |
Moss Unicorn
| Purple Amethyst x12 |
White Diamond x4 |
Wind Pegacorn
| Purple Amethyst x9 |
White Diamond x5 |
Green Emerald x4  |
Dragon Pegacorn
| Purple Amethyst x5 |
White Diamond x11 |
Green Emerald x6 |
Princess Pegacorn
| Purple Amethyst x8 |
White Diamond x9 |
Green Emerald x10 |
Star Light Unicorn
| Purple Amethyst x12 |
White Diamond x9 |
Green Emerald x10 |
Red Ruby x4  |
Icy Fire Pegacorn
| Purple Amethyst x10 |
White Diamond x12 |
Green Emerald x11 |
Red Ruby x10 |
Angel Pegacorn
| Purple Amethyst x11 |
White Diamond x10 |
Green Emerald x19 |
Red Ruby x14 |
Tiara Unicorn
| Purple Amethyst x10 |
White Diamond x16 |
Green Emerald x17 |
Red Ruby x22 |
Fancy Pants Unicorn
| Purple Amethyst x15 |
White Diamond x20 |
Green Emerald x18 |
Red Ruby x16 |
Blue Saphire x10  |
Lightning Pegacorn
| Purple Amethyst x22 |
White Diamond x15 |
Green Emerald x23 |
Red Ruby x18 |
Blue Saphire x20 |
Robot Unicorn
| Purple Amethyst x20 |
White Diamond x23 |
Green Emerald x20 |
Red Ruby x33 |
Blue Saphire x26 |
Phoenix Pegacorn
| Purple Amethyst x40 |
White Diamond x37 |
Green Emerald x29 |
Red Ruby x23 |
Blue Saphire x30 |
