by Jo Wicht and Duncan Miller

For several decades small mines in southern Namibia have produced an attractive banded agate marketed as lapidary material. The major source has been a mine on Ysterputs farm, producing blue lace agate. It was promoted widely by the late George Swanson who owned the mine, so this material with its wavy blue and white lines is quite familiar. What is less well known is that the blue lace agate from Ysterputs is accompanied by several minerals forming aesthetic, collectable specimens; and that there are other sources of blue chalcedony in the near vicinity. Several anecdotal accounts of the Ysterputs Blue Lace Agate mine have been published but until now there has been no detailed description of the occurrence or the mineralogical composition of the agate, and the associated late-stage minerals have not been described, nor illustrated, in publication.