Other than the more generic and typically used gemstones including from diamonds, rubies, sapphires, and emeralds, pearls and opal[24] have also been defined as precious while in the jewellery trade. Up for the discoveries of bulk amethyst in Brazil from the nineteenth century, amethyst was considered a "precious stone" likewise, https://certified-gemstones85175.blogsvirals.com/26529502/the-gemstoneuniverse-diaries