Level Up Dice - Mini Snowflake Clear QuartzClear Quartz, also known as Rock Crystal or Ice Crystal, is composed of silicon dioxide. Clear Quartz can be transparent or opaque; you may also see striations or fractures contained within the stone. We recommend that you do not roll your semi precious stone dice on a surface harder than they are (i. e., glass or wood tables). We suggest you roll them in a dice tray to prevent possible chipping or breaking.