This is a job lot of 6 small opal doublets of various sizes and origins. A doublet consists of a thinly sliced sliver of natural opal, which is mounted upon an underlay of dark slate, which optimises the colours and sparkles. To give you an idea of the sizes: The round blue one has a diameter of 8mm, the small round blue one has a diameter of 6mm. The green drop-shaped one is 9mm long. All stones have plenty of colour in them. The one with the most striking colours, however, has a few nibbles round the edges. We don’t use doublets in our jewellery, but these stones can be used by those who do to make very nice pendants with them or to replace missing doublets in existing pieces. Alternatively, they can just be used as mineral samples for display.