SS refers to 'Stone Size' and is followed by a number, as well as the size in millimeters. In general, SS2 - SS10 are the small sizes used for nail art, beauty, fine jewellery and tooth gems. SS12 - SS20 are often used in dance, costume, craft, cardmaking and textiles. SS30 - SS48 are more commonly used for Irish dance, theatrical costumes and costume jewellery. For more information on rhinestone sizes, see our Ultimate Guide here.