31. The artifacts recovered included a great many fire cracked rocks and chert flakes. 32. It includes large flint and chert bifacials that may be of Heavy Neolithic origin. 33. They made spear points of jasper, quartz, shale, or black chert . 34. When a chert stone is struck against an iron-bearing surface sparks result. 35. Flint and chert are the most commonly knapped materials and are compact cryptocrystalline quartz. 36. The quarries consist of beds of white-grey limestone separated by chert beds. 37. Plants demonstrate best the great value of the exceptional preservation of the Rhynie chert . 38. This is a chert containing oxidized iron in the form of hematite and goethite. 39. Some of the chert clasts actually contained fossils. 40. Here radiolarian cherts overlie spilites and volcanic rocks.
