How To Make & Choose Semi Precious Stones
How to Make Semi-Precious StoneSome semi-precious stones are used in the same unsculpted, natural form in which they are found; however, most are cut and polished long before they find their way to a jeweler’s display.
There are two main classifications of stone cuts. The first is known as a cabochon, whereby the stone is cut into a smoothly shaped dome using a grinding wheel and polished to show off the stone’s color or surface properties. These stones are usually opaque, such as opal, turquoise or variscite. The second, known as faceting, involves the use of a faceting machine to cut the stone by polishing small, flat windows known as facets at regular intervals and exact angles.
Faceting is used primarily with transparent stones to show off the optical properties of the interior, maximizing the reflected light to make the stone appear to “sparkle”. There are many commonly used shapes for faceted stones, as you’ll see if you stop by any display of diamond jewelry.
Faceting is an extremely precise science. If the angle of the cut is too steep or too shallow it will oppose the stone’s natural interior. Light will pass through rather than being reflected toward the jeweler, and the gem will appear to be very ordinary rather than extraordinary. Some cutters will use a special curved lap for faceting; however, it is far more common to see a jeweler using a faceting machine to hold the stone onto a flat lap to cut and polish each facet.
Today’s Technology
There are many treatments used to enhance the color and clarity of the stone, and while some treatments are discouraged due to the instability of the resulting gem (its tendency to revert back to its original form) there are many that are widely used to create the exquisite semi-precious gems that you see shining in the display window at your local jeweler’s.
• Heat-Heat is often used by jewelers to improve gemstone color or clarity. Stones such as aquamarine and tanzanite are regularly heat treated to removed undesirable undertones, and many precious gems such as sapphires and rubies are treated to a variety of heat treatments to improve their color and clarity before being released onto the market.
• Irradiation-Many consumers are astonished to find out that the stones in their favorite pieces of jewelry have been irradiated. Most blue topaz is irradiated to change the color from white to blue, and green quartz is often irradiated to achieve its yellow-green color. While some gems passing through improper channels may still emit low level radiation, stringent requirements on stones both imported and domestic that pass through legal channels and undergo these treatments ensure that they are safe for the public.
• Synthetic stones-There are many, many synthetic semi-precious stones available on the market today. Some are manufactured in an attempt to create a less expensive version of a costly stone, as in the case of cubic zirconia; however, some are simply lab grown gems that have thrived due to the lack of impurities in a controlled environment and which are perfect replicas of those stones found in their natural form. While naturally grown gems are considered to be more valuable among the gemstone community, whether they are grown by gemologists or Mother Nature has no effect whatsoever on whether they are considered to be precious or semi-precious.
Choosing Semi-Precious Stones
The single most important thing to consider when selecting which semi-precious stone will adorn your jewelry is your personal preferences. What stone puts that bounce in your step or inspires you to take one last glance in the mirror before walking out of the house? Color, clarity and carat are used to determine the market value of each semi-precious stone, but it is your personality that will determine the value of the stone to you.
