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.

Quartz:

With its uniquely mystical appearance, quartz was the “rock crystal” used in ancient times to make crystal balls. It was believed to attract energy and is still considered to be spiritual today. The gemstone was once believed to be a compact form of ice. In fact, the Greeks originally named quartz “krystallos,” meaning ice, but this terminology soon applied to any type of crystal.

Often identified by its six-sided prism shape, quartz is the most common mineral on Earth, found in nearly every environment throughout the globe. With a ranking of 7.0 on the Mohs Scale, it is a component of almost every rock type and occurs in virtually every color imaginable. Quartz has a great amount varieties that are well-known by other names, including amethyst, citrine, ametrine, rock crystal, agate, druzy, chalcedony, tigers eye and many more. There are also several varieties that hold the name “quartz,” including rose quartz, smokey quartz and rutilated quartz.

The pale pink color of quartz is known as rose quartz, the traditional gift for couples celebrating their 2nd anniversary. It is a delicate powder pink color that ranges from transparent to translucent. Transparent rose quartz is quite rare and is usually so pale that it does not show much color, except in large sizes. The translucent quality of rose quartz is much more common and is used for jewelry and carvings.

Rose quartz is probably one of the most prized stones for its mystical properties. Known as the “Heart Stone,” it is believed to have incredible powers to balance emotions and open the heart. Folklore says rose quartz can comfort brokenhearted people, bringing healing and clarity to the heart and allowing the wearer to learn to trust again. The stone is also said to foster happiness and the joy of life by bringing about contentment in love and filling one with optimism, tenderness and gentleness.

In addition to helping with romantic love, rose quartz is believed to enhance all other forms of love as well, including self-love, platonic and maternal. Its loving, nurturing energy is said to take away fears, resentment and anger and replace them with feelings of higher self-esteem and confidence. This soothing stone is also thought to balance emotions and heal emotional wounds. It is said to be especially powerful in times of stress or loss, bringing peace and calm to the wearer.

Ranging in color from nearly black to smoky brown, smoky quartz is transparent and owes its warm earthen hue to exposure to natural radioactivity. Care must be taken since its rich color will fade in the sun. Spelled either “smoky” or “smokey,” this variety of quartz is often incorrectly called “smoky topaz.”

Smoky quartz is believed to help dissolve negative energy, release stress and relieve depression. It is said to be a mild sedative with a relaxing effect that calms, soothes and restores balance and harmony. Folklore says the gem can embrace dark areas with light and love and therefore clear and cleanse the body both physically and emotionally. Smoky quartz is thought to be a warm, friendly and down-to-earth gem.

Rutilated quartz is a type of transparent rock crystal that contains long, fine needles of rutile crystals (titanium dioxide). These highly valued inclusions form a landscape of shining gold needles in an array of patterns that is breathtakingly beautiful. These golden inclusions are also known as Venus hair, Cupid’s darts and fleches d’amour (“arrows of love”). There is a less well-known variety called tourmalinated quartz that, instead of golden rutile, forms black or dark green tourmaline crystals.

Although rutilated quartz is usually cut as a cabochon, it can be a difficult stone to attain a smooth surface without pits. This is because rutile ranks a 6.0 on the Mohs Scale, while quartz ranks 7.0. The difference in hardness between the two materials, and because of the way rutile forms inside, causes problems when cutting. Each final cut piece is unique, with no two being exactly alike. Modern folklore says rutilated quartz brings forth each person's strengths, originality and ability to relate to others.