Gemstone Learning Guide

Color
Jewelers describe the color of a gemstone in terms of three characteristics: hue, saturation, and tone. A gemstone's basic color is its hue, and those with purer hues (for emeralds, green; for sapphires, blue; and for rubies, red) are generally considered more valuable. Often, however, a hint of another color can be detected. Sapphires will range from purplish blue to greenish blue; emeralds, yellowish green to bluish green; and rubies, orangey red to purplish red. Saturation is a measure of the intensity or purity of a gem's hue and is determined by the degree to which gray or brown hues mute its defining color. Value tends to increase with saturation, so a fully saturated purplish blue sapphire may well be more expensive than a muted pure blue one. The tone of a gemstone, a measurement of its lightness or darkness, is usually given as light, medium-light, medium, medium-dark, or dark.
Clarity
A flawless gemstone is rare and usually extravagantly priced. As with diamonds, most gemstones have inclusions, or tiny mineral flaws, that can be seen under magnification or by the careful eye. Sapphires tend to be moderately included, while emeralds and rubies are usually heavily to moderately included. Make sure that any inclusions in the stone do not penetrate deeply into the gem, as this may cause it to break or crack. Clarity grades range from VVS (very, very slightly included) to I3, in which inclusions are prominent and severely affect the gemstone's beauty.
Cut
A gemstone's cut refers to its proportions and symmetry. It is essential in making a gemstone look appealing--the stone should be symmetrical in all dimensions so that it will appear balanced, and so that its facets will reflect light evenly, providing good brilliance. Color should also be taken into account when cutting for optical efficiency. If a stone's color is highly saturated, a shallow cut will allow it to pass more light, while a deeper cut may increase the vividness of a less saturated gem. There is no generally accepted grading system for gemstone cut.
Size
Though a gemstone's weight is usually given in carats, this may not give an accurate idea of its size, because different types of stone have different densities. Therefore, a 1-carat sapphire or ruby will be smaller than a 1-carat emerald, though they have the same weight, because sapphires and rubies (both a form of the mineral corundum) are more dense than emeralds.
Illustration of gemstone dimensions
Gemstones can also be measured in dimensions (diameter, length, and width). It is important to know the dimensions to ensure that the gemstone weight will be visible and well proportioned in the setting.
Treatment
Gemstones are often treated to enhance color and fill cracks. Please note that, if a gemstone has been treated, this information will be provided in the specifications on the stone's product detail page. There are various accepted techniques, depending on the type of stone. For example, oils and resins are frequently used to fill surface-reaching fissures in emeralds and rubies. This process is not permanent, however; if a treated ruby or emerald is subjected to high heat from a jeweler's torch, an ultrasonic or steam cleaner, or even hot dishwater, the filler may leak out of the stone. Sapphires and rubies are often heated in a kiln or furnace to enhance their color. Such heat treatment, which is considered permanent, has been used for centuries. Lightly colored sapphires may also undergo diffusion treatment. This is done by heating a stone in the presence of coloring elements such as titanium or iron, which causes a thin layer of color to be diffused into the stone's surface. Because this color layer is so thin, a diffusion-treated sapphire should not be repolished.
Care
To clean gemstone jewelry, first wipe it with a soft cloth to remove any dirt. Emeralds require only the use of a soft cloth, as cleaners may damage these soft gems. Sapphires and rubies can be cleaned with either an ultrasonic cleaner or a solution of one part ammonia to six parts water, with a soft brush. Store your gemstone jewelry in a soft cloth pouch or jewelry case so it does not touch other pieces in your collection. As with all jewelry, normal wear and tear can loosen prongs and settings, so it is a good idea to have it checked by a professional jeweler who can make repairs as needed.

Your Guide to Engagement Rings

You're ready to pop the question, now you just need the ring. With the vast array of options, how's a guy supposed to choose? Don't panic, we’ll step you through the process (and nudge you whenever you start to hyperventilate). In the end, we want to make sure you get the most for your money--a ring that will leave her breathless, while leaving your budget intact. We’ll run through the steps first, and then introduce you to Amazon’s Create The Ring of Your Dreams tool to take you the rest of the way.

Set your budget

How much should you spend? The old "three months’ salary" advice may be a useful starting point, but it’s not a hard-and-fast rule. You can spend less and still find a terrific ring, or you can spend more and splurge on size or quality. The only "correct" amount to spend is the amount that fits your budget. With our enormous inventory, Amazon can help you find a beautiful ring at any price point. Create your own ring or shop pre-set engagement rings.

Know her style

The best way to find out what she likes is to ask her. Better yet, look at rings together. If you want the ring to be a total surprise, though, you’ll need to do a little sleuthing. Pay close attention to her style. Check out the jewelry she wears. Is it traditional? Romantic? Modern? Practical? Does she like showier pieces, or more subtle styles? What color of metal does she usually wear—white or yellow?
Don’t be afraid to enlist her friends and relatives to help. Ask her mom, her sister, or her best friend for advice (but first, make sure they can keep a secret).

Choose the setting

The diamond you choose will be mounted in a ring, which is called the setting. That setting can be simple, or elaborate. It can hold the diamond flush with the band, or raise it high above it. It can highlight the diamond in a simple way, or it can shimmer with accent stones or fancy metalwork. Again, knowing her style will help you choose the right setting. Looking for something tried-and-true? Some of the most popular and classic diamond settings are the solitaire, the cathedral, the three-stone, and the channel setting.
Consider her hand size when you choose the setting. A broader band will balance long, slender fingers, while something more petite will complement a smaller hand. For a flattering result, look for a diamond and setting that are proportionate to her ring size.
When you choose the setting, you’ll also need to choose the metal: White gold or yellow? Fourteen karat? Eighteen karat? Or platinum? See our Precious Metals Guide for help.

Choose a diamond shape

We're talking overall geometry of the diamond here. By far, the most preferred diamond shape is round-brilliant. With its 360 degree symmetry, it gives off the most sparkle. Princess shapes are the second most popular choice, with their clean square lines, modern look, and beautiful sparkle. Other choices include the regal-looking marquise (which has the advantage of lengthening the finger), the classic emerald cut, and the radiant cut (a blend of emerald and round-brilliant). The oval diamond is an elongated variation of the popular round brilliant, while the asscher diamond resembles an emerald cut, but with a squared shape and unique blocked corners. Other fancy shapes, such as pear, heart, and cushion, round out the list of possibilities.