Precious Gems
We say precious gems, but do we know what exactly makes them precious? I’ll try to answer this question. In a few words gems have been priced for their durability and beauty. Their value varies from the rarity of a stone, and skill with which it was cut. Since the ancient times lots of stones and minerals were used as gemstones. Years passed and some of them became worthless and priceless.
Second role of precious gems after the ornamentation was the currency for many inhabitants of different countries and regions. We know that all the times precious gems have been used as a way to keep wealth or as exchanging value in distant lands.
The one of the most important gem features is the ability to refract light. That depends of gemstone’s properties and of course the skill of its cutter. The most popular optical properties used are the gem stone color and refractive index. However there are much more like dichroism, dispersion, absorption play of color, chatoyancy, and luster. Asterism is an effect that is sometimes displayed, but not measured. By the way – by refraction we understand the measure how light comes through the gem. Dichroism describes gemstones’ tendency to display different colors under different angles. Absorption and dispersion show the amount of absorbed or dispersed light in a given spectrum. Asterism and chatoyancy are similar produce concentrated bands of light such as in tiger-eyes or stars. Luster describes how the level of shine in the stone.
The great impact on a beauty of the precious gem has the cut. Until cutters will do their work you maybe even will not have a possibility to recognize in a piece of rock or crystal precious gem. At first craftsmen should cut and polish the stone and therefore release the beauty of the gemstone. The precious gem stone cutting is not only a process where cutter must make a flat top that tapers to a point at the back. It is much harder than it seems – it is a precise mathematical operation where craftsman must calculate the angles of the facets to bring the most ‘fire’ and beauty to the gem. And what is more – cutter must do it very careful not to weaken the stone with the clumsy cut. Stones must be cut at certain degrees to prevent the stone from breaking or cleaving.
After all precious gem’s price and value is based on its type, size and quality. One thing is for sure – the rarity of a stone-type goes along with its size. Small gems that are widely available are relatively cheap, but large ones are very rare and have bigger per carat price. Quality also has a greatest impact on a gem price. Mostly the price doubles from a low grade gem to a same type high quality gemstone. And what is more – even the political, economic, and military conditions within the country or region that produce gemstones may affect the prices as well.
