Buy Semi Precious Gemstone Online? Gemstone is basically the name of an organic material, a rock or a mineral piece. These gems are basically cut into right shape and then polished to get the finished product like jewelleries or some beautiful accessories. Basically these gemstones are created by minerals but some kind of gemstones are also formed with the help of rocks. These rocks will be used for making of the gemstones. Usually all the gemstones are really hard but when Jewellery is being made with the gemstone, then depending on the kind of jewellery, minerals which are soft can also be used.