The metamorphic jewels are always found in the form of large stone slabs. These jewels and gems are formed. deep under the fourth or the fifth layer of the earth's strata. Buried for thousands of years in the nature's womb, in the deep gravels of earth, these jewels and gems go on changing their colours and shades in a continuous process. Many times, when the earth's womb boils up to throw up the volcanic lavas, these gems and jewels resurface and some of the liquid lava gradually turns up to form the most sought-after gems and the jewels also. But that is a very long process. This metamorphic wealth can be found from three sources, (i) metamorphic rock, (ii) igneous rock and (iii) sedimentary rock.
The metamorphic rock: This is the self-changing high quality stone stratum and the gems take shape as the nature's bounty. These are believed to form into gems and jewels after the continual process wherein the hard rocky stratum works as the base on which the pressures of earth's upper strata and heat automatically works. To cite an example when a heap of mud or that of soft soil turns into hard slabs, a large part of it is turned into Garnets. In the same way lime stones develop into marbles. Similarly, a slab of hard transferable carbon turns into a marvellous rock of Diamond from unbearable heat and limestone may get converted into Ruby if subjected to continuous heat and pressure.
It is estimated that it takes more than 7,000 years or more for a slab of coal to turn into a rock of diamond. All these precious jewels take thousands of years, Emerald taking about 7,000 to 8,000 years to be formed, the Yellow Sapphires some 6,000 years and mud and soft soil blocks more than 3,000 years to become Garnet blocks. This very Garnet may turn into Ruby if it gets heated for another thousand years or so.
Sedimentary rock: These rocks are formed when animals, creatures, trees, plants, logs, etc gradually drift down the earth's strata and are affected by nature's changing seasons and onslaughts and ultimately turn into hard rock’s; some of them turn into jewels and gems. They are light, smooth and glowing. Tourmalines, Opals, Cat's Eye, Moon Stones, Peridots and Lapis Lajulis are made thus.
Besides mines, seas also provide us jewels. In fact gems were in existence even before man was born. But in today's world, gems and jewels are being made artificially. But most of them are meant only for decoration. They do not have the efficacy to nullify the evil effect of planets or remove illness. In Mumbia and panna many industries which are engaged in cutting and polishing diamonds and other precious stones.
Cutting of gems was being carried out even in olden times (in 14th century B.C.).