Cut: Refers to the geometric shape and proportions of a gemstone. A gemstone’s cut is what most directly affects its sparkle or brilliance.

Facet: A flat cut on the surface of a gemstone.

Fire: Flashes of rainbow colors. Also called “dispersion.”

Hardness: Resistance to scratching. The higher the number, the more resistant.

Hue: Another word for color.

Luster: The shininess of a jewel.

Opaque: The opposite of transparent. Light cannot pass through an opaque gemstone, therefore they do not have any sparkle or fire.

Saturation: This term refers to how pure or deep a gemstone’s color is. Some gemstones, like aquamarine, have a naturally low saturation (very light blue) while other gemstones, like amethysts, can have very high saturation (rich, dark purple).

Sparkle: The white light leaving a jewel, traveling upward, which is visible to the eye. Sparkle is often referred to as “brilliance.”

Toughness: Resistance to breakage.

Gemstone Shapes & Cuts
These are the common shapes or cuts for gemstones, each lending a different look and allure.

Baguette: Baguette means “stick” or “rod” in French, which makes it a very appropriate name for this gemstone shape. Diamond baguettes are often used as accent stones to flank a primary stone.

Brilliant: Any gemstone cut with 58 facets, which produces the maximum possible sparkle. A brilliant cut can have several shapes, including round, oval, pear, radiant and heart.

Cabochon: This shape features a rounded, perfectly smooth surface instead of facets. It is the oldest gemstone shape and is commonly used with opaque stones such as opal, jade and turquoise.

Cushion: A very popular style for most of the 19th century, cushion shapes are slightly domed with rounded corners that make the stone look like a pillow. In fact, this shape is often referred to as a “pillow cut.” It looks particularly beautiful in candlelight.

Emerald: With its long, steep facets, emerald cuts tend to flash rather than sparkle.

Fancy: Technically, this term refers to any type of gemstone that isn’t round, but many jewelers reserve it to describe the more exotic gemstone shapes such as marquise, heart, pear and trillion.

Heart: Often described as a custom cut, heart-shaped gemstones are very popular for pendants.

Marquise: According to legend, this shape was commissioned by King Louis XV to resemble the smile of his mistress, Marquise de Pompadour. Ideal marquise cuts have a length to width ratio of 2:1.

Oval: Similar to the round shape, oval gemstones produce a high amount of sparkle and fire.

Pear: This is a classic teardrop shape that is ideal for earrings and pendants.

Princess: This a relatively new shape that combines the sharp, flat edges of an emerald shape with numerous small facets, which produce both sparkle and fire.

Radiant: This shape is similar to emerald, but it adds extra facets on the edges and corners to increase the gemstone’s sparkle.

Round: This classic shape produces maximum sparkle and fire, making it an ideal shape for diamonds.

Tapered Baguette: A tapered baguette is a baguette shape with one end that is narrower than the other.

Trillion: A very striking, usually three-sided shape, trillion gemstones (especially diamonds) are celebrated for the intense fire they produce.

The Mohs Scale
The most common measure of a gemstone's degree of hardness is based on the Mohs Scale. Devised by German geologist Friedrich Mohs in 1812, the Mohs Scale grades minerals on a comparative scale from 1 (very soft) to 10 (very hard).

Hardness is generally associated with durability and the ability to resist breakage. When referring to gemstones, however, hardness more accurately means the stone's ability to resist abrasion. What the scale means is that a mineral of a given hardness rating will scratch other minerals of the same rating, as well as any minerals of a lower hardness rating. For example, rubies and sapphires, which are composed of the mineral corundum and have a Mohs rating of 9, will scratch each other, as well as topaz (rating 8) and quartz (rating 7). But they will not scratch diamonds, which are rated 10 and considered the hardest substance.

The numeric values assigned to each interval of hardness are not equal. Some stones are disproportionately harder than others. Because Mohs Scale wasn't made for exact precision, it uses half numbers for in-between hardness ratings.

Tourmaline:

Tourmaline occurs in virtually every color of the spectrum, with an unlimited range of solid and mixed colors in all imaginable shades. According to an ancient Egyptian legend, this is the result of the gemstone traveling along a rainbow from the Earth’s heart, up to the sun. On its journey, the legend says that tourmaline collected all the colors of the rainbow, which is why nowadays it is called the “Rainbow Gemstone.”

Tourmalines displaying just one color are quite rare since one crystal usually shows two or more shades or colors. In fact, the name “tourmaline” has been derived from the Singhalese expression “tura mali,” which translates to “stone of mixed colors.” Even two stones cut from the same rough mother crystal will often show different colors, a characteristic that makes tourmalines so attractive and sought-after.

Tourmaline crystals come from a mineral group that usually forms in various combinations of elements. The slightest changes in composition will result in completely different colors. Thus, it is possible that in one naturally grown crystal, there will appear completely different colors. Some will show only slightly shaded color fields, while others will display contrasting colors and defined color zoning. Tourmalines rank a hardness of 7.0-7.5 on the Mohs Scale and may be as small as a knitting needle or as thick as a thigh. They are easily available in sizes of up to 5.00ct.

Different shades of colored tourmalines have been assigned specific names. Bi-colored and multi-colored tourmalines have several names for the common combinations of colors. Crystals with red or pink cores and green borders are called watermelon-tourmalines. Stones with colorless crystals and black tips are called Maur’s Head or Moor’s Head, while colorless crystals with red tips are called Turk’s Head. If the color zones are arranged one on top of the other, the stone is considered a rainbow tourmaline.

The red variety of tourmaline changes its name based on the coloring in different types of lighting. Deep red tourmaline named rubellite shows the same fine ruby-red shade in daylight and in artificial light. Should the color change when the source of light changes, the stone is simply called a pink tourmaline. With its exquisitely intense coloring, rubellite was once the victim of misidentification for rubies in the Russian crown jewels.

A recognizable variety of the gem is simply called, green tourmaline. It comes in a variety of green shades, including leek-green, intense yellow-green, olive-green and brownish-green. Chromium-tourmaline is the trade name for the emerald-green variety. The most rare and highly coveted green hues are the blue-green stones often called African tourmalines and the bottle-green gems referred to as Brazilian tourmalines.

Perhaps the most beautiful variety is the Paraiba tourmaline. It ranges in color from electric blue to neon blue-green to sizzling turquoise. Discovered in the Brazilian state of Paraiba, its spectacular color is due to the presence of a small amount of copper. A study by the German Foundation for Gemstone Research recently also discovered a surprisingly high content of gold in the stones. While the average gold content of the Earth’s crust is 0.007 parts per million, Paraiba tourmalines contain a remarkable 8.6 parts per million. So if they were not so breathtaking, the gems might be in danger of being crushed to acquire their gold.

Paraiba tourmalines are mined near a village called Sao Jose de Batalha. In 1989, the miners discovered a new vein of gem-quality stones with extraordinarily bright shades of blue and green. Hand-excavated shafts and tunnels are up to 60 meters deep and the tourmaline is found only in pencil-thin veins. Because of the difficulty in mining, supply will always be limited and Pariaba tourmalines will always be rare and expensive. Dealers all over the world are competing for the Paraiba tourmaline, which means that it can command retail prices more than $20,000 per carat.

In the year 2000, electric yellow tourmalines were found in Malawi in East Africa. With a clear and pure color, they were deemed “canary tourmalines”. Only 10 percent of all the mined yellow stones are gem-quality and when cut, more than 95 percent of the harvest will weigh less than 1.00ct. Yellow tourmalines are considered to be the only gemstones that have a fine scent. This is because their crystals are often embedded into black material that must be removed before the stones are cut. An owner of a Malawi gemstone mine discovered the black matter was easily removed when the rough crystals were boiled in water and lemon juice. Ever since then, yellow tourmalines from Malawi not only resemble fresh lemons in color, but also in their scent before they are cut.

Other tourmalines are called “indigolith” if they are blue and “dravite” if they are golden to dark brown. Black tourmalines are known as “schorls” and are mainly used for engraving. Although they were used as mourning jewelry, ancients believed black tourmalines to be stones that protected against negativity and strengthened the heart.

Tourmalines are piezoelectric, meaning they can generate electrical charges when heated, compressed or vibrated. They then become polarized crystalline magnets and can attract light objects. The Dutch, who originally brought the stone to Europe, knew about this effect and used heated tourmalines to extract ashes from their pipes. The stones were even favorite toys of Dutch children before their gem quality was established. Because the gem’s electrical charges attract dust and small materials, some believe that wearing pink tourmalines will attract love and green ones will attract success.

Tourmaline has often been called the “muses’ stone” because it is believed that its imaginative colors contain inspirational powers that grant enlightenment, enable creativity and express an artist’s mood. Due to the stones’ energetic conductivity and vast array of elements, they are thought to have powerful healing abilities and protect against many dangers. Tourmaline is supposed to be an especially powerful influence on love and friendship, fostering compassion and cool headedness. It is considered the traditional gift to give couples celebrating their 8th wedding anniversary.

Ever since the ancient days, the gem has been attributed with magical powers. Today, specific colors of tourmaline are thought to hold individualized powers. Black is believed to strengthen the immune system and bring luck and happiness when rubbed. Green tourmaline is said to encourage communication and bring success, while blue is a balancer that stimulates other tourmalines’ effectiveness. Watermelon tourmaline is believed to increase perception and creativity, while balancing passivity and aggressiveness. Pink is thought to promote peace, increase spiritual understanding and bring forth love and friendship.