As he notes, with crystals and feathers, it also depends on where the inclusions are in the diamond.
A modern ring bought from a jewellery manufacturer will entail extra costs associated with design, workmanship, brand etc in addition to the value of the materials. Therefore the ring will never be worth you paid for it.
If you are buying a ring, you will always get better value purchasing one from a reputable antique jewellery dealer. I highly recommend Karen Deakin in Sydney. She is very knowledgable, has all her gemstone jewellery valued at the Gem Studies Laboratory and her prices are excellent. https://www.karendeakinantiques.com/gallery/
