These flat rate boxes of heated treated spalls and flakes of Pasco coral are ready to work upon arrival. Coral is essentially million year old coral heads from when Florida was a shallow sea. Over time, silica replaced the organics and now we have some really nice rock as a result that breaks sharp and clean once heat treated. There is a ton of work that goes into finding, spalling and heating coral, but the end result is very worth it. It knaps pretty well once heat treated, but I still consider it better for the intermediate or skilled knapper as some of the pieces are a bit abstract and require greater skill to thin down. Boxes are mixed with both white and colorful pieces. The color is a bit more rare in good quality knapping rock. I strive for function over fashion and the white typically yields slicker rock on average but when the color is good, I certainly use it as it’s a special treat!