200 Sliver Chests are available in a hidden Treasure Room. You get a key every 500 orbs and spend it on one of these or a 5 key Gold Chest.
10 of them include icons and colours while the remaining 190 randomly contain one of these:
- 50-1000 mana orbs
- 5-30 diamonds
- 100-200 mana orbs and 5-10 diamonds
- 1-3 shards of 1-2 types (or if you have 100 of all of them, 100 mana orbs)