Transparent Glass Cabochons, Half Round/Dome, ClearSize: about 14.5~15mm in diameter, 4mm thick.â Material: The clear cabochons are made of glass, highly transparent, with good gloss. One side of the cabochons is flat, the other side Is dome shaped. â Glass cabochon with non-calibrated round and flat-back design has a slight magnifying effect, can magnify the photos & designs and make them stand out. â Wide Usage: Good for handmade crafts and photo pendants making. You can use the same shape blank trays to customize personalized jewelry.