The dry milled fireclay is a 20 mesh, granular, plastic fireclay. This can be used as firing clay for pottery. Physical Properties: Pyrometric Cone Equivalent: Orton Standard Cones 31 Quantity Required to lay 1,000 9x4.5x2.5 Bricks (2292 x 114 x 63 mm) Brick = 475 lbs. 216 kg (Dipping Consistency) Particle Size (Dry) Maximum Retained on 12 Mesh (1.40mm opening) Less than 1.0% Maximum Retained on 16 Mesh (1.00mm opening) Less than 2.0% Typical Through 100 Mesh (0.15mm opening) 75%