Calibrated gemstones
What are calibrated gems you ask? I'll tell you. Calibrated are called gem stones that has standard dimensions (size is measured in mm) and that are cut to fit ready made jewelry. That means that a lot of gems are cut to compatible dimensions that are known as calibrated sizes. These gemstones fit into a variety of different settings. So you can always ask your jeweler to help you and select the best combination for you.
Today we have watch and jewelry industry develops very vast. So to fit the continuously growing demands of high end technologies is used micro calibration. It is machine cut precisely calibrated crafting process. Each and every calibrated gem from diamond to ruby is crafted to the most precise specifications for size, shape, color and quality.
It is possible only due to CNC process (computer numerical control) and the other computer aided technologies that had been originally developed to comply with the precision-engineering standards demanded in the optics and electronic industries. And what is more developers constantly create specialized tools for the needs of gemstone calibration to ensure precision.
Could you imagine that all these processes and mechanisms started long, long ago when jewelers faced the problem of setting the different stones using standard settings and forms? After calibrating sizes, matching stone pairs, refining their shapes all this gem mounting system remained weak, inefficient and results looked clumsy. People almost had no experience and the ability to make tight fitting caps. However there were problems - they were bad smiths but the top of the non calibrated gem is a cone with a constant angle. So to get good bond jewelers had to fit the top of the stone exactly to the cap. For those time is was a lot more difficult than you might think. All these difficulties made the hastened the progress in the sphere of calibration of gemstones.
So I guess you understand that if you want to buy a suitable for any costume jewelry gem stone you'd better search for calibrated gemstones. Nowadays almost all gems are available in the wide range of calibrated shapes and sizes. That is including many fancy shapes. Large fine stones may be sold in free sizes but generally they are cut in standardized dimensions.
When shopping for calibrated gem stones along the term "calibrated" you can see the following parameters: color description, clarity, image light source, shape, cut, weight, enhancement and its origin. If it is not written on the label or anywhere else you can demand this information from your jeweler or the salesman.
For example we'll take natural round hessonite. Its color description is medium dark yellowish orange. The clarity is "eye clean to slightly included". The shape is round. It has the Portuguese cut. It is calibrated to 6.75 x 6.75 mm with the weight of 1.41 CTS. It can be found in Madagascar and was not enhanced.
I hope the information about gem calibration was full enough so you can freely buy calibrated gems and what is more - distinguish them from non calibrated ones.