Buying Guide to Gemstones Jewelry

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They say diamonds are a girl’s best friend. But jewelry set with a beautiful gemstone is also very special, as gemstones are available in many colors, sizes and shapes.

Jewelry: Gemstones

Don’t have a specific idea of what you’re looking for? Answer the following questions to help narrow down your search.

Who is it for and is it for an occasion?

Are you looking for a gemstone or one of the 12 popular birthstones? Or simply picking out something to complement your favorite party dress? Knowing about the person’s tastes is going to help decide whether you want a brightly colored piece of gemstone jewelry or something a little more understated.

What kind of gemstone jewelry are you interested in?

Fortunately, you can find gemstone settings in necklaces, earrings, bracelets, rings and broaches. Some common gemstones available include:

  • Agate
  • Amber
  • Amethyst
  • Aquamarine
  • Blue Topaz
  • Carnelian
  • Chalcedony
  • Citrine
  • Diamond
  • Emerald
  • Garnet
  • Jade
  • Moonstone
  • Onyx
  • Opal
  • Pearl
  • Peridot
  • Ruby
  • Sapphire
  • Smokey Quartz
  • Tanzanite
  • Tourmaline
  • Turquoise
  • White Quartz
  • White Topaz

Are you looking for precious or semi-precious gemstones?

When thinking about categories of gemstones, it's only natural to assume that precious stones are always worth more than semi-precious stones, but that's not necessarily the case. The terms "precious" and "semi-precious" have been around for centuries, but the terms don't necessarily relate to an individual gemstone's value.

The easiest way to tell the difference between the two categories is to know that only four gems fall into the precious stone category: diamonds, emeralds, rubies and sapphires. These stones are categorized together because of their rarity and vibrant colors. They're formed from some of the hardest minerals on earth.

Colored gemstones like amethyst, topaz, opal, garnet, citrine, and dozens of others are categorized as semi-precious. These stones are prized for their beauty and range of colors: the blues of aquamarine, the purples of amethysts, the red garnets, citrine's shades of yellow and opal's iridescence, to name a few.

While precious stones traditionally cost more than semi-precious stones, occasionally you'll find some relatively cheap precious stones and some very expensive semi-precious stones. The value of a gemstone specifically comes from the stone's quality and size.

What color gemstone are you looking for?

Color is the main distinguishing characteristic of a gemstone. Gemstones come in a wide spectrum of colors to suit anyone's taste. From the reds of garnets to the yellowish-green of peridot, a stone's color can be one way to evaluate its value.

You can't judge a gemstone's color just by looking at it. Three characteristics help determine the true color of a gem: hue, saturation and tone. Hue refers to the shades of color within a stone. A gemstone rarely consists of one color, and upon close examination, you can find shades of other colors within it. A stone with fewer hues has more value.

While hue refers to the different colors within a gemstone, saturation refers to how intense and pure the hue is. Gems with higher saturation rates have very pure colors with few hues, particularly lacking shades of gray or brown. The higher the saturation rate, the more valuable the stone. Jewelers use saturation to determine how to cut a gemstone, as a better stone has consistent saturation throughout.

Tone describes the lightness or darkness of a gemstone's hue. The spectrum of tones ranges from colorless to black and includes five distinctions: light, medium-light, medium, medium-dark and dark. The most prized stones are with medium-light to medium-dark tones.

These three characteristics combine to determine the true color of a gemstone. When looking at specific gemstones, look at the intensity of the color to help determine the quality of the stone.

What size gemstone are you looking for?

Colored gemstones are bought and sold according to a calibrated millimeter size, such as 2mm (length) x 1mm (width) x 1mm (depth). Know though, that stone cutting is not an exact science, so in many cases you’ll find jewelry listed with a guaranteed minimum millimeter size, in addition to carat weight.

Gemstone weight is measured in carats: one carat = 0.2 grams or 1/142 of an ounce, or points. For example, one carat is divided into 100 points; therefore, ¼ carat is considered 25 points.

Are you looking for something that won't chip?

If you want a gemstone ring or bracelet for everyday wear, consider a harder stone that isn't prone to chipping. You want your jewelry to be able to withstand every day wear and tear, not crack (literally) under pressure.

Natural, Lab-Created, and Color-Treated Gemstones

When you buy a gemstone, consider whether the stone is natural or treated. Gemstone enhancement has become a very common and accepted practice because it greatly improves the appearance of the stone. The vast majority of stones are treated in some way. Treated or enhanced gemstones are generally more cost-effective than natural or non-treated gemstones.

Color-Treated Gemstones

Sometimes gemstones are color-treated to either enhance or modify their natural hue or to alter them into a new color altogether. Some treatments or enhancements are permanent, while others are temporary. Two common methods of color treating gemstones include:

1. Altering the physical structure of the gem at the atomic level, which in turn causes light to refract through the gem in a new way, creating color. Intense heating treatment and irradiation both work in this way.

2. Adding or removing color in some way. Dyeing, coating and diffusion all work by adding a chemical of some sort to the gem to adjust the gem’s natural color. Bleaching treatments are occasionally done to some gems in order to lighten or lower the intensity of a color. For a better understanding, here’s an explanation about each method.

B- Bleaching: The use of chemicals or other agents to lighten or remove a gemstone’s color. Pearls and ivory may be bleached to lighten their color.

C- Coating: The use of surface enhancements such as lacquering, enameling, inking, foiling, or sputtering of films to improve appearance, provide color or add other special effects.

D- Dyeing: The introduction of coloring matter into a gemstone to give it new color, intensify present color or improve color uniformity.

F- Filling: As a by-product of heat enhancement, the presence of solidified borax or similar colorless substances that are visible under properly illuminated 10X magnification.

G- Gamma/Electron Irradiation: The use of gamma and/or electron bombardment to alter a gemstone’s color. It may be followed by a heating process.

H- Heating: Heating is one of the most common treatments used to enhance the natural beauty of colored gemstones. This permanent process can dramatically improve the color and/or clarity in a number of stones, including sapphires, rubies, diamonds, aquamarine, amethyst, tanzanite, topaz, tourmaline and other stones.

I- Infilling: The intentional filling of surface breaking cavities or fractures usually with glass, plastic, opticon with hardeners and/or other hardened foreign substances to improve durability, appearance and/or add weight.

Some gemstones that are commonly color-treated or enhanced include diamonds, pearls, topaz, quartz, jadeite, citrine, ruby, aquamarine and tanzanite. Some of the gemstones that are not commonly enhanced include garnet, peridot, green zircon and tourmaline.

Lab-Created Gemstones

Lab-created gemstones are made of the same mineral composition as natural gemstones. They're created in a controlled setting with equipment that simulates the high pressure and heat nature uses to create real gemstones far beneath the surface of the earth. A lab-created gemstone is identical to natural gemstones in every way: color, hardness, composition, luster, looks, etc.

The one difference between a lab-created gemstone and a natural gemstone is that the natural gemstone most likely has flaws called inclusions. Because a laboratory can control mineral composition, heat and pressure, lab-created gemstones have no inclusions. While having a perfect lab-created gemstone sounds nice, a too perfect gemstone can sometimes look unnatural or phony.

Flaws or inclusions of natural gemstones are caused by minute traces of minerals that are trapped within the gemstone during the gemstone’s crystallization process. When extraneous gases and other minerals mix in the molten mass before it cools and crystallizes, these inclusions form. The fewer inclusions a natural gemstone has, the higher its clarity rating, which also means a higher value when being appraised.

It may seem odd that we will pay much more for a natural gemstone that will have inclusions than we would for an identical, flawless lab-created gemstone, but our culture and the jewelry industry's marketing efforts have placed a higher value on natural gemstones. Remember, a lab-created gemstone is identical to a natural gemstone, except the lab-created gemstone is flawless. Because of the high price of natural gemstones, many gemstones sold today are lab-created.

Gemstone Cuts

Marquis or heart-shaped cut? Briolette or cushion? Choosing a cut is usually a matter of personal taste. Below is a short guide to some common gemstone cuts.

Cut Shape
Baguette Oblong, step cut Baguette Cut
Briolette Tear drop shaped, covered in facets, pointed end Briolette Cut
Cushion Square, rounded edges Cushion Cut
Emerald Rectangular with beveled corners and step-cut facets Emerald Cut
Heart Heart Heart-Shaped Cut
Marquise A long oval that’s pointed at each end Marquise Cut
Oval Egg Oval Cut
Pear Cut Oval with a point on the end of the stone and depth to the underside Pear Cut
Trilliant Triangle with shortened corners Trilliant Cut

Buying Tips

Not quite sure what to look for in a gemstone? Quality gemstones will have the following:

  • A bright, vivid color
  • A clear, transparent body
  • No visible flaws when viewed in the face-up position
  • A cut that reflects light evenly across its surface when in the face-up position

Birthstones

Birthstone jewelry makes a great present for both friends and family or a great personal choice. Not sure which stone is representative of each month? Check the chart below for the most commonly used birthstone.

Month Birthstone Color Meaning
January Garnet Garnets are found in many colors from deep red to green. Garnets are said to represent friendship and loyalty. January Birthstone - Garnet
February Amethyst Known for its striking shades of purple, the amethyst is a type of quartz. The word “amethyst” derives from Greek and means “not intoxicated.” This meaning has expanded to encompass sincerity and peace. January Birthstone - Garnet
March Aquamarine* Aquamarine is typically a pale blue-green. Aquamarine is said to represent health and courage; the gem also has nautical connotations thanks to its meaning (the word “aquamarine” means “water of the sea”). January Birthstone - Garnet
April Diamond (Due to cost, white topaz or other white stones may be substituted.) Traditionally white, but colored diamonds are also available. Diamonds represent love and evoke feelings of permanence and longevity; they also represent 60th anniversaries. January Birthstone - Garnet
May Emerald* Emeralds are noted for their iconic green coloring. Like diamonds, emeralds are said to represent love, but they also represent the spirit of rebirth as well as fertility. January Birthstone - Garnet
June Pearl Pearls are noted for their creamy white color, but can also be found in many other shades from rose to black. Pearls symbolize purity. January Birthstone - Garnet
July Ruby* Rubies are—of course—red, although the precise shade of red may vary. The ruby is a symbol of nobility and is also said to represent good fortune. January Birthstone - Garnet
August Peridot Peridot is found in shades of olive or lime green. Peridot represents strength and power, as well as protection. January Birthstone - Garnet
September Sapphire* Blue is the predominant color of sapphires, but other colors exist, including shades of purple and green. Sapphires are associated with wisdom and protection. January Birthstone - Garnet
October Opal* Opal is known for its play of color. It might show one, two or a rainbow of colors. Opals are a symbol of creativity and confidence. January Birthstone - Garnet
November Citrine Citrine is a golden yellow. Citrine is associated with health, happiness, clarity. January Birthstone - Garnet
December Blue Topaz Comes in three shades of blue, pale sky blue, cool Swiss blue and deep London blue. Blue topaz evokes images of wind, sky and water. Blue is the color of calmness, quiet and relaxation. January Birthstone - Garnet

*These gemstones are available in lab-created versions.

You want your jewelry to last a lifetime. That means treating it with the utmost care.

Regular cleaning of gemstone jewelry is essential to maintain shine and brilliance of gems. When wearing gemstones, they can get dirty from soaps, lotions and even the skin's natural oils. Even when you are not wearing them, they collect dust. You can learn to clean gemstone jewelry by yourself, but you should also know about the different cleaning services a professional jeweler can provide.

You can give your gemstone jewelry a touch up cleaning at home. First wipe it with a soft cloth to remove any dirt. Then mix a mild detergent with warm sudsy water--never use boiling or hot water--and gently place your jewelry pieces in the mixture to soak them. Take a small soft brush--an eyebrow or lipstick brush works best--and dipping it in the sudsy mixture, gently brush the gemstone. Thoroughly rinse the jewelry to get rid of all the suds. Finally, pat them dry with a soft cloth or a jewelry polish cloth. You can also use liquid jewelry cleaners sold by many department stores. Be sure to follow all the written precautions and instructions before cleaning. Do not use toothpaste or any other abrasive cleaner on gemstones or mounting.

It's also a good idea to have a professional jeweler clean your jewelry once a year. During a cleaning your gemstone will receive a professional shine and polish, checking of settings to make sure they're secure and any needed repairs of loose or bent prongs that hold your gemstones in place.

Nowadays, ultrasonic cleaning machines are available to clean jewelry by bombarding it with sound waves. While the vibrations do shake off dirt, they can also cause damage to the gemstone, especially brittle stones like emeralds. The shaking can also potentially enlarge stone inclusions, which makes the gem less attractive and valuable. A home ultrasonic cleaner should be used with extreme caution. An ultrasonic cleaner can clean ruby, sapphire, diamond, iolite, amethyst, citrine, garnets, chrysoberyl and unadorned gold jewelry, but it may damage gems like emerald, pink tourmaline, peridot, pearls, coral, lapis lazuli, malachite, turquoise and any gem that has many inclusions. When in doubt, don't use it.

Leaving jewelry out on the dresser or bathroom sink can lead to loss and damage. Store your gemstones in a jewelry box that’s lined with velvet or faux suede.