This specification covers the determination of muscovite mica splittings of standard commercial grades and specifies the maximum allowable physical defects for each grade. It is applicable to commercially available natural muscovite mica splittings regardless of the basic color of the mica or its source. This specification covers thirteen grades of mica splittings based on size and form classification. Mica splittings shall meet the specified physical property requirements such as size, thickness, defects, and absence of any foreign matter. Where specified, the visual quality shall conform to the description of the visual category specified such as V-1, V-2, V-3, V-4, V-5, V-5.1, V-6, V-7, V-8, V-9, V-10, V-11, and V-12. The method of sampling of mica splittings in bookform and loose with powder form are specified and method of calculation of defect percentage is given.

1.1 This specification covers the determination of muscovite mica splittings of standard commercial grades and specifies the maximum allowable physical defects for each grade. It is applicable to commercially available natural muscovite mica splittings regardless of the basic color of the mica or its source.

1.2 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.

1.3 This standard is very similar to ISO 6386. It is expected that materials would be classified identically using the criteria of either standard. The grades shown under “ASTM Grade No.” in Table 1 and Table 2 are shown under “Old Grade No.” in ISO 6386-1981.