Kaiserstuhl, Germany. This specimen comes with a label, in German, from the Collection of G. Schneider, obtained by Minerals Unlimited in 1956. The label gives the mine as "Abershafthausen", but I cannot validate that information.
Minute (25X magnification needed) water-clear octahedrons in a few tiny pockets in fibrous wollastonite matrix. Also present are minute phillipsite, aegirine, fluorescent grains of opal, and possible natrolite.
2x3cm Weight 8.5 grams