Power Crystals are ore-like blocks added by PowerCraft. They come in eight colors: Orange, Red, Green, Darkblue [sic], Lightblue [sic], Purple, Cyan and Yellow. They spawn between the Y level 5 and 15, with about 3 veins per chunk, with each vein containing 1-4 crystals.
Unlike most ores, the Power Crystals can be broken and collected without a pickaxe or any other tools. The crystals emit a light level of 16, but this can disabled in the config. If enabled, the Power Crystals will make a jingling noise (like the sound of gaining Experience Points) when a player is within 6 blocks of it. The Power Crystals are used to create various blocks and items in PowerCraft.
When crossed with a Laser, the Power Crystal will cause that Laser to become the color of the Power Crystal.