Blue onyx pocket ashtray

Very beautiful ashtray, pocket tray or even onyx paperweight, with magnificent colors: a caramel veining on a background of old blue where we distinguish multiple layers by transparency. The label on the back indicates that it is onyx from argentina, which was worked in italy. It must date from the 60s. This ashtray is in good general condition, but has 3 or 4 very small chips on 2 edges. It measures 7.8 cm side, 1.8 cm tall and weighs about 220 g.