Gemstones are pieces of mineral crystals/rocks/other organic resources that are cut, polished and refined to be used in the manufacture of jewelry and other embellishments. Gemstones are largely classified into precious and semi-precious stones. Diamond, Ruby, Sapphire and Emerald are considered precious stones while the other stones fall in the category of semi-precious ones.
Though Diamonds are one of the most valuable gemstones, the finely-cut Ruby, Sapphire and Emerald top the list of precious gemstones; the reasons for which are stated below-
Although Diamonds are rare, but Ruby, Sapphire and Emerald are rarer, which makes them more exquisite and treasured stones. As per the available statistics, global retail sales of diamond jewelry remained flat in US dollar terms in 2016; this reflects the stagnancy in the supply-demand of diamonds as people are getting more inclined towards buying other precious stones.
Ruby, Sapphire & Emerald are more durable than Diamond. This is evident from the very fact that diamond exhibits perfect cleavage, which means, it can be easily split by a single blow whereas the other precious stones possess no such cleavage, and are hence, much preferred due to their longevity.
It is a myth that diamonds are the most valuable gems whereas the fact is Ruby, Sapphire and Emerald are much more valuable. The prices of all the precious stones of different sizes are mentioned in the below table-