GEMSTONE HARDNESS SCALE: DISTINGUISHING THE DURABILITY OF COLORED GEMSTONES
Gemstones are like people—some are tougher than others. The hardness of a gemstone is determined by something called the Mohs scale, a scale which rates a gemstone on its hardness measured from 1 to 10, 1 being the softest a stone can be and 10 being the hardest. However, hardness alone is not the only aspect to take into account when considering a gemstone’s durability—though it is the criteria most frequently used.
Another handy indicator of durability is stability—as in the physical stability of the stone when exposed to various environments or elements. For instance, diamonds can be exposed to mild acids such as vinegar, whereas stones like aquamarine and peridot should not. In certain cases, prolonged exposure to light can compromise the color (and quality) of the stone. Yellow-brown topaz can fade after prolonged exposure to light, so these types of stones are best worn with evening attire or brought sparingly out into the light of day. Another stone whose stability is finicky is the opal. Opals actually require water to maintain their stability and durability and can become dehydrated and crack without it.
With regard to designer jewelry using the Mohs scale as a reference for how to treat your gemstones is usually more than adequate, because designer jewelry is usually worn in settings where exposure to harsh cleansers or chemicals isn’t likely to occur. If we’re at parties, we don’t have to worry about getting bleach on our jewelry. Likewise, in most of our daily activities at work we don’t have to worry about accidently spilling vinegar on our gemstones. However, in both of these scenarios we do have to worry about repeatedly bumping our designer jewelry against hard surfaces or dinging said jewelry on any of the numerous items kept in our purse or work bag. In situations like these it’s good to know which gemstones can’t take a beating from mundane tasks.
As a general guideline, gemstones with a Mohs scale of 7 are considered safe to be worn on a more frequent basis. The rule of thumb is that gemstones with a Mohs scale of 7 or higher are generally considered safe for regular use, while gemstones that rate below 7 are best reserved for special occasions. However, for wedding rings and engagement rings—designer jewelry items that are intended to be worn every day—a rating between 8 and 10 is recommended. In terms of what gemstones are suitable for daily use, diamonds (10), sapphires (9), and topaz (8) tend to be the better choice; whereas softer gemstones, such as tanzanite (7), peridot (6.5), and fluorite (4), are probably safer being worn on special occas