P3X-562
From The Stargate Omnipedia
A world once home to the Unity crystal species. The entire population was attacked by an army of Jaffa whose lord feared the creatures. Very few survived to tell the tale.
The surface of the planet is covered in pollen-colored dust which is only offset by the destroyed crystals.
DETAILS
HOME TO - Unity
FIRST APPEARED - Cold Lazarus
KEY EPISODE
Cold Lazarus - SG-1 visits P3X-562 and discovers a graveyard of blue crystals, apparently destroyed by Jaffa weapons fire.