You can make Sandy Crystals with one Sand and two Crystals
You can smelt Crystal Geodes in a furnace or blast furnace for one Crystal, or you can break them for 1 to 8. Fortune effects the drop rate.
The current ores and crystal(s) in the mod
Crystal Geodes generate in caves below y level 64, and are extremely common.
Sandy Crystals generate in sand at y levels below 128. Most commonly found in deserts. NOTE: They don't generate in red sand.
You can smelt Sandy Crystals for two Clear Glass.
The different glasses in the mod. They can be crafted the same way stained-glass is, but with Clear Glass instead.