Reasons for the Jewellery
Many reasons for the Jewellery has been used such as Currency, Artistic display, Wealth display, Storage, and Status. Other reasons are:
Functional use - There are many items of Jewellery which are originated as purely functional items but evolved into decorative items as their functional requirement diminished, these items are brooches and buckles.
Symbolism - Jewellery can also be symbolic of group membership. As in the case of the Christian crucifix or Jewish Star of David, or of status, as in the case of chains of office, or the Western practice of married people wearing a wedding ring.
Protection - Wearing of amulets and devotional medals to provide protection or ward off evil is common in some cultures; these may take the form of symbols - such as the ankh, stones, plants, animals, body parts - such as the Khamsa, or glyphs - such as stylized versions of the Throne Verse in Islamic art.
Keeping large amounts of wealth stored in the form of Jewellery in most cultures. And Jewellry used to create Jewellery as a means to store or display coins or in the form of wedding dowries in numerous cultures.
Gemstones are identified by gemologists
Gemstones are identified by gemologists. The first characteristic a gemologist uses to identify a gemstone is its chemical composition. Gems are characterized in terms of refractive index, dispersion, specific gravity, hardness, cleavage, fracture, and luster. They may exhibit pleochroism or double refraction. Who describe gems and their characteristics using technical terminology specific to the field of gemology.
Next, many gems are crystals which are classified by their crystal system such as cubic or trigonal or monoclinic. They may have luminescence and a distinctive absorption spectrum. For example, diamonds are made of carbon (C) and rubies of aluminium oxide (Al2O3). Another term used is habit, the form the gem is usually found in. For example diamonds, which have a cubic crystal system, are often found as octahedrons.
All gemstones have some characteristics
Many gemstones are used in even the most expensive jewellery depending on the brand name of the designer, fashion trends, market supply, treatments etc. Others are too common and are given a semi-precious status. Most gemstones have good hardness and a high index of refraction.
All gemstones have some characteristics falling short of perfection though; even the seemingly perfect Diamond has four directions of cleavage. Since quartz is everywhere especially in common dirt and dust. Any material that is softer may be scratched during ordinary wear. Nevertheless, diamonds, rubies, sapphires and emeralds still have a reputation that exceeds those of other gemstones.