People have always loved precious stones, materials, and highly valued jewelry as an art. Gem stones were especially adored due to their price and beauty.
Most mineral crystals grow from molten rock deep within the Earth. Crystals often form in nature when liquids cool and start to harden. It takes a lot of time for a crystal to form, and not all of them can become precious gemstones.
Apart from our favorite diamonds, pearls, sapphires and rubies, there are very rare gemstones, which are hard to find. That's why they are very expensive as well.