This one has a quite a few grams of sterling silver casting grains embedded in organic epoxy.

https://www.bitmit.net/en/img/trade_uploads/2012/09/12/orgonite-pendant-amethyst_515b7.jpg

https://www.bitmit.net/en/img/trade_uploads/2012/09/12/orgonite-pendant-amethyst_515b70.jpg