Natural horn buttons, approximately 12.5mm across and 2.5mm thick. (Matching 10mm buttons shown in the 2nd photo are available separately.) These are a "dirty" beige colour overall, with some darker taupe markings. The buttons are convex on the back and concave on the front. The backs are more polished than the fronts, which look semi-matte.
I take care to pick the best available buttons for each order but, since horn is a natural material, there may be slight imperfections and variations in colour. Please wash with care - avoid using acidic cleaners and high heat.