Mineral particles, <2. 0 mm in equivalent diameter, ranging between specified size limits. The names and size limits of separates recognised in the USA are: very coarse sand (Prior to 1947 this separate was called "fine gravel;" now fine gravel includes particles between 2. 0 mm and about 12. 5 mm in diameter), 2. 0 to 1. 0 mm; coarse sand, 1. 0 to 0. 5 mm; medium sand, 0. 5 to 0. 25 mm; fine sand, 0. 25 to 0. 10 mm; very fine sand, 0. 10 to 0. 05 mm; silt, 0. 05 to 0. 002 mm; and clay (Prior to 1937, "clay" included particles <0. 005 mm in diameter, and "silt," those particles from 0. 05 to 0. 005 mm) <0. 002 mm. The separates recognised by the International Society of Soil Science are: (i) coarse sand, 2. 0 to 0. 2 mm; (ii) fine sand, 0. 2 to 0. 02 mm; (iii) silt, 0. 02 to 0. 002 mm; and (iv) clay, <0. 002 mm.