Science of Gemstones
Gemstones are minerals with special beauty and physical properties which attracts attention to process them to personal adornment and decorative purposes.
Most of us are attracted to gemstones and are familiar with a few of the most popular and well known varieties, but there are many minerals possessing qualities that make them desirable as gemstones. Natural gemstones are referred to as rough, while they are then regarded as gems after the lapidary process. Note: lapidary is the act of cutting and polishing of gemstones (it would be discussed in another post). The term gemstone is applied to those minerals that have undergone lapidary processes.
Gemstones are most times modified into two classes; precious and semi-precious can be used to distinguish the more from the less valuable gems. Note: though, this isn’t an ideal way of gemstone classification because the quality of a gem is based upon its beauty, durability and rarity. Consistently, diamond, emerald, ruby and sapphire has being classed as precious stones, but at times opal, pearl, and alexandrite have also being considered precious.; tourmaline, beryl, garnet, topaz, zircon, peridote (olivine), spinel, turquoise have being categorized as semi-precious stones.
The chief uses of gemstones are in jewellery making and in adornment. In the past, early gems were valued and used much as they are today for personal adornment but of equal and greater importance to the wearers were their presumed magical powers. To each mineral or gemstone was attributed a certain virtue and thus, gemstones were worn as amulets, or talisman. Of the approximately 2,500 known minerals only about 70 possess one or more of the qualifications that place them in the special characteristics of gemstones. Most members of their relatively small groups are rare and only about 20 are generally encountered as gemstones.
The characteristics that make gemstones are;
Beauty of a gemstone is observed from its colour because it is the most dictating property. Where most gemstones possess different colours, diamond and tourmaline for instance has all the colours. A gemstone needs be hard to be durable. The most important criterion determining the quality of a gemstone is its rarity; a gemstone has to be rare before it commands value.
Other factors which may affect the value of gemstones are fashion and portability.