Hardness is one thing, Aside from quite a few others, which differentiates sapphires from other gemstones. It really is second only to diamond and scores a 9 outside of ten on the hardness scale. Do sapphires are available in any other colour Apart from blue? Thanks Navratan to your attempts https://sitesrow.com/story7744706/natural-yellow-sapphire-from-sri-lanka-no-further-a-mystery