These are natural and unused loose opals in calibrated size 5mm. ready to use in jewelery. hand cut beautifully and full of colors. we are new to e-commerce platform but we have been doing gemstone business from generations so you can trust us for quality and honesty. There can be little bit variation in height. Please give us a positive feedback If you like the goods as it can help us to grow our business and if you have any problem with the goods please contact us before giving any negative feedback.