Description: Here's (a 12x18.4mm part of) a little piece of black-pepper-and-white-salt matrix from Långban (collection id 10SESJcx3, overall dimensions 36x30x23mm). So what's what? The light parts of the matrix are mostly carbonates (calcite and/or dolomite with some Mn); Tilasite may also be present. What about the lustrous dark grains?

All pictures, text, design © Forum FMF 2006-2025