Section 329IAC10-2-206.3. "Wentworth grain-size scale" defined

  3. "Wentworth grain-size scale" means grain-size divisions defined by the following:

Grain Size Scales*
Grade Limits in Millimeters		Grade Name
Lower Limit	Upper Limit
256 and above		Boulders
64	256	Cobbles
16	64 Coarse	Pebbles
4	16 Fine
2	4	Granules
1	2 Very Coarse	Sand
0.5	1 Coarse
0.25	0.5 Medium
0.125	0.25 Fine
0.062	0.125 Very Fine
0.031	0.062 Very Coarse	Silt
0.016	0.031 Coarse
0.008	0.016 Medium
0.004	0.008 Fine
0.002	0.004 Very Fine
Below 0.002	0.002	Clay

  *IDEM, Requirements for Describing Unconsolidated Deposits, revised November 19, 1988. (Solid Waste Management Division; 329 IAC 10-2-206.3; filed Aug 2, 1999, 11:50 a.m.: 22 IR 3770; errata filed Sep 8, 1999, 11:38 a.m.: 23 IR 27)