This is one of Strathearn's "Nature Inspired" weights consisting of Scottish sand and ground granite encased in a clear glass weight. As far as I know to date Strathearn only made these in a large size ranging from 2.7 " to about 3.0". According to Dave Moir these Stoer weights were quite difficult to make as they had to be very careful and maintain a constant glass temperature to keep the sand and granite from falling through the weight. This P2 series was also extended to the PSF22 series, a Top faceted weight with five side facets. A very attractive weight with different shadings depending on the composition density. Production quanities are unknown at this time.