Ratan Mica Exports Private Limited supplies Processed Mica Block Sheets. Ratan Mica Exports Private Limited is an ISO 9001:2000 accredited company. Processed Mica Block Sheets are classified into thirteen size groups [ranging from OOEE Special down to No. 7] and obtained in size as large as 30 - 35 cm sq. [12 - 14 inches sq.] beyond which is practically rare and far too expensive. Processed Mica Block Sheets is available in sheets with both random [natural] and calibrated thickness as per demand. Knife or scissor dressed sheet mica with irregular shape and a minimum thickness of 0.18 mm [0.007 inch or 7 mils] are called mica blocks.