Gemstone Buying Guide

Gemstone Buying Guide

Gemstones have long held cultural significance in the fashion world as dazzling accessories and signifiers of important milestones. From classic sparkle to exotic hues, gemstone jewelry can amplify personal style, perfect an outfit, and make a meaningful gift or keepsake. Whether you're expanding your personal jewelry collection or giving a gift to someone you care about, keep reading for more tips on how to buy a gemstone.

Gemstones 101

A gemstone is a mineral or other organic material that is mined from the earth or sea, and is often valued for its beauty and rarity. In their rough form, gemstones are asymmetrical and dull before they are cut, polished, and turned into jewelry. Many people use the terms "jewel" and "gem" interchangeably, but there is a distinct difference. A gemstone is simply the stone before it is set into jewelry. Once a gemstone is fashioned into a piece of jewelry, it is considered a jewel. Gemstones come in a brilliant array of colors and consistencies and can be found in various locations and climates all over the world.

Precious vs. Semi-Precious Gemstones

Every type of gemstone is completely unique with a very specific mineral makeup that gives it distinct characteristics. Some gemstones are perceived as more valuable than others based on rarity, accessibility, purity, and, in some cases, cultural significance. The four gemstones that are most commonly considered precious are diamonds, rubies, sapphires, and emeralds. These four stones are considered precious because of the time it takes to create them, their rarity, and their quality or chemical makeup. Though all other gemstones technically fall into the semi-precious category, many of them can be just as precious or rare as diamonds and rubies.

Precious Gemstones

  • Have been considered more rare and valuable since ancient times when used in cultural rituals
  • Typically pure in color, have extremely strong chemical makeups, and are very rare
  • Make up the majority of gemstone purchases

Semi-Precious Gemstones

  • Sometimes just as rare as precious stones, but not perceived as having the same value
  • Wide array of primary and secondary hues, unique inclusions, and varying chemical makeups

Organic Vs. Mineral Gemstones

Organic Gemstones

Organic gemstones come from living organisms like plants and animals, and are typically farmed or harvested from the earth and sea. The most common organic gemstones are pearl, amber, and coral.

White pearl in a diamond halo silver ring

Pearl: A pearl is an organic gemstone produced inside an oyster as the result of the oyster protecting itself against some form of irritant, like sand. The oyster forms layer upon layer around the particle until a lustrous pearl is formed. Pearls can be found in both freshwater and saltwater oysters.

Pear shaped amber in stering silver ring

Amber: Amber is a rare, organic mineral formed from the fossilized sap or resin of ancient and extinct pine trees. Because amber is fossilized, it sometimes traps organisms such as insects and plants within its translucent orange material. Amber can also be found in pink, gold, and brown colors.

18k rose gold plated coral oval ring

Coral: Like pearl, coral is an organic gemstone found in water. It is a skeletal structure built by small ocean animals called coral polyps. When the coral polyps die, they leave behind a hardened skeleton that is then collected and used for decor and jewelry.

Mineral Gemstones

Mineral gemstones are mined from the earth. Each type of mineral gemstone undergoes a specific combination of heat, pressure, and time that creates the hardened crystal structures unique to the individual gemstone.

Pair of round diamond earring

Diamonds: A diamond is a colorless or almost colorless concentration of pure carbon. It is the strongest known mineral in the world, formed under immense heat and pressure deep in the earth. Though diamonds are perceived as colorless, they come in a range of colors from clear to yellow to brown and all shades in between.

Round blue sapphire earrings in a halo setting

Sapphires: A sapphire is made from aluminum oxide that has been under high heat and pressure over thousands of years. Sapphires come in many colors including yellow and pink, but the most prized is the blue sapphire.

Cushion cut ruby earring in a halo setting

Rubies: A ruby, formed from aluminum oxide, is actually a type of sapphire that gets its deep red color from inclusions of the metal chromium.

Pear shaped emeral earrings in a halo setting

Emeralds: An emerald is in the beryl gemstone family, meaning it is made of beryllium aluminum with inclusions of iron, vanadium, and chromium that give it its green or blue-green color.

Lab-Created Gemstones vs. Natural Gemstones

Both precious and semi-precious gemstones can be found in nature or created in a lab. There is not a chemical difference in natural and synthetic gemstones — they have the same look, color, and quality. Every gemstone has a very specific mineral and chemical makeup, which can be replicated in a lab to create an authentic gemstone in a shorter amount of time than it takes for the earth to create one naturally. There are many advantages to lab-grown gemstones: they are conflict-free, eco-friendly, more affordable than natural stones, and more quickly produced.

    Lab-Created Gemstones:

  • No mining required
  • Identical to natural gemstones in every way
  • Created in a shorter amount of time than mined gemstones
  • Less expensive

    Natural Gemstones:

  • Must be mined from the earth or sea
  • Take hundreds of thousands of years to form naturally
  • Very rare and extremely valuable
  • More expensive than lab-created stones

The Four C's of Gemstones

Close up of a round gold diamond ring resting on a branch

It's no secret that rarity, durability, beauty, and size contribute to the price of a gemstone. If you've been doing some engagement ring shopping, you also might be familiar with the "four C's" as they apply to diamonds. However, the value of every gemstone is also determined by the 4 C's: color, cut, clarity, and carat weight. Choosing a gemstone can be a process, but learning the 4 C's will teach you how gemstones are valued and allow you to narrow down your options.

Industry standards might not always align with what you're looking for. For example, you might love the look of a stone with less saturated color, while industry standards call for high saturation. So remember your personal preference and always purchase the gemstone you will love rather than the one you think you should love.

1 Color

Illustration of a gemstone color

Gemstones come in nearly every color imaginable and when it comes to buying gems, color is the most important value factor. In fact, one gem variety can have many different hues. For example, sapphires, tourmalines, and garnets all come in blue, pink, and yellow hues.

A gemstone's color is broken out into three categories: hue, tone, and saturation. These categories and criteria determine color quality and price. Typically, vivid hues and medium tones make for the most sought-after gems, but it's important to remember that color preference is personal.

Tone: Also known as value, tone refers to the lightness or darkness of color. Tones can range from clear to black, and varying tones can render varying hues. For example, light or clear tones in an emerald will make a light green, whereas a dark-toned emerald will look more like deep forest green.

Saturation: Also known as chroma or intensity, saturation refers to the amount of color present in the stone. When you think of the perfect ruby, you probably imagine a deep and perfect red that has no trace of yellow, pink, or orange. This is an example of flawless saturation. A gemstone with excellent saturation reflects a pure color that is uninterrupted by brown or grey tints.

Hue: There are six primary hues: violet, blue, green, yellow, orange, and red. Between the primary hues are secondary hues like blue-green. Gemstones that have pure primary colors are the most valuable (emerald, sapphire, ruby). Gems that are very pale, very dark, or are tinged with brown or grey are less valuable.

  • Remember, color preference is personal. Industry standards might not align with what you're looking for, so always purchase the gemstone you love rather than the one you think you should love.

Gemstones by Hue

Gemstone hue is an aspect of gemstone color, but doesn't include other factors such as tone and saturation. Colored gemstones technically come in thousands of hues that are all variations of six primary hues: violet, blue, green, yellow, orange, and red. Some gemstones are a single, primary hue. Others fall anywhere along this spectrum, being a combination of primary hues, or including more than one hue, such as tourmaline, opal, and topaz. Below is a list of common gemstones by hue.

Pink Hue: rose quartz, topaz, ruby, diamond, tourmaline

Red Hue: ruby, carnelian, coral, zircon, garnet

Yellow Hue: citrine, diamond, sapphire, garnet, peridot, amber

Green Hue: emerald, jade, malachite, alexandrite, topaz, zircon

Blue Hue: sapphire, zircon, lapis lazuli, turquoise

Purple Hue: amethyst, alexandrite, tanzanite, purple jade, opal, garnet

Black Hue: hematite, onyx, diamond, obsidian, beryl, pearl

Brown Hue: topaz, diamond, amber, citrine, smoky quartz

White Hue: diamond, pearl, zircon, moissanite, opal, moonstone

2 Clarity

Illustration of a gemstone clarity

Gemstone clarity is determined by how visible a stone's inclusions are and whether there are any foreign inclusions within the stone. Because of the way gemstones form in the earth, many stones naturally have inclusions. Inclusions are any foreign objects such as dust, air pockets, liquid, insects, or other minerals that have been enclosed within a gemstone during its formation. Gemstones with few to no inclusions are considered quite valuable, whereas more inclusions typically drive down the price and value of gemstones. A few exceptions to this rule are certain inclusions that make gemstones rarer, such as sapphires that have inclusions that look like a star.

3 Carat Weight and Rarity

Illustration of a carat weight and rarity

Gemstones are sold by weight, not size. The carat is the standard weight measurement used, which converts to one-fifth of a gram. Because each stone is made up of a different mineral, the density varies from stone to stone. For example, a one-carat emerald and a one-carat ruby will weigh the same, but the ruby will be smaller because it is a denser stone.

Certain gems are rarely found in large sizes. This means you can expect to pay much more per carat for stones like ruby, sapphire, spinel, alexandrite, garnet, and emerald.

4 Cut

Illustration of different gemstone cut

A gemstone's "cut" refers to the way it has been faceted and styled to refract light. Unlike simply tumbling and polishing a stone, jewelers use faceting to amplify a stone's brilliance by geometrically cutting multiple flat facets into the gem. Cut and shape are often confused, but even though both cut and shape are gemstone styling terms, cut is solely focused on faceting a gemstone to showcase its brilliance. Shape is the general outline of the stone when it is viewed from above. Many retailers use the terms "cut" and "shape" interchangeably. However, noting the difference between the terms is important because there are certain cuts that can be applied to different shapes. For example, the popular brilliant cut is a style of faceting that can be used on heart-shaped, round, and square gemstones.

Gemstone Cuts and Facets

Illustration of a step cut stone

Step Cut

Used on baguette, emerald, and asscher gemstones, the step cut involves rectangular and square facets that create a deep, mirror-like look.

Illustration of brilliant cut stone

Brilliant Cut

A brilliant cut can be applied to round or square gemstones. It is one of the most popular cuts because of its intense sparkle. The brilliant cut has many variations based on the shape and size of the gemstone.

Illustration of ceylon cut stone

Ceylon Cut

A Ceylon cut is a combination of both step cuts and brilliant cuts. A Ceylon gemstone has a brilliant-cut crown and a step-cut pavilion.

Illustration of a rose cut stone

Rose Cut

A rose-cut gemstone is faceted similarly to a brilliant cut, but has a flat bottom and consistent repetition of same-sized triangular facets over the entire crown. Their flat bottom makes them weigh less than other cuts.

Illustration of cabochon cut stone

Cabochon Cut

Cabochon gemstones are tumbled and polished until they reach a glossy shine. Then, they are cut to fit into particular settings, but otherwise left alone. Cabochon gemstones don't have facets, and feature a smooth domed crown.

Illustration of a barion cut stone

Barion Cut

A barion cut is a combination of a step cut and brilliant cut in the crown of a gemstone. It can be applied to square, rectangular, and round shaped gemstones.

Illustration of a checkerboard cut stone

Checkerboard Cut

A checkerboard cut is similar to a rose cut, but uses square facets instead of triangular facets to achieve a checkerboard look. This cut is common on cushion-shaped gemstones.

Illustration of a eight cut stone

Eight Cut

The eight cut is a simplified brilliant cut, pared down to only eight facets around the crown.

Illustration of an old mine cut stone

Old Mine Cut

The old mine cut is the predecessor to the brilliant cut. Still faceted for ultimate sparkle, old-mine cut gemstones have a taller crown and larger facets than the traditional brilliant cut.

Popular Gemstone Shapes

A gemstone's overall shape refers to the outline that can be seen from above the gemstone. Many of the cuts discussed above can be applied to and modified for various gemstone shapes. Below is an overview of popular gemstone shapes.

Illustration of a heart shaped gem


The heart-shaped gemstone features the traditional romantic symbol with a modified brilliant-cut facet pattern to suit its unique silhouette.

Illustartion of a marquise shaped gem


A marquise-shaped diamond has two curved edges that come to two opposite points. Like the oval, round, and pear shape, a marquise-shaped gemstone is faceted with a variation of the brilliant cut.

Illustration of emerald shaped gem


Emerald-cut gemstones feature a flat table and are usually rectangular with step cuts and about 50 facets. An emerald cut has more of a "mirror" effect than a "sparkle" effect on gemstones.

Illustration of asscher shaped gem


Asscher gemstones are simply the square version of an emerald cut, including the square and rectangular mirror-like step facets.

Illustartion of a round shaped gem


The round gemstone is possibly the most popular shape, especially for classic solitaire settings. Round gemstones usually feature a brilliant, rose, or cabochon cut.

Illustration of an oval shaped gem


An oval shaped gemstone has an elongated round shape with a modified brilliant cut featuring more facets than the traditional round brilliant cut stones.

Illustration of a cushion shaped gem


A cushion-cut gemstone is a variation of the square or rectangle, with slightly curved edges and rounded corners.

Illustration of a baguette shaped gem


A baguette-shaped gemstone is a long, narrow rectangle and is often faceted with step cuts similar to emerald cuts.

Illustration of a pear shaped gem


Pear shaped gemstones have one rounded edge that comes to a single point, resembling the shape of a raindrop. This shape offers a vintage look and brilliant cut faceting that is modified to suit its shape.

Illustration of a trillion shaped gem


A trillion cut gemstone is a three-sided, curved triangular gemstone averaging 31 to 43 facets.

Illustration of a princess shaped gem


The princess-cut diamond is just as popular as the round brilliant cut and is very similar in brilliance. Up to 76 facets give this square-shaped gem a sparkle unlike any other cut.

Illustration of a briolette shaped gem


A briolette-shaped gemstone is similar to the pear shape, but it is faceted on all sides and cut to hang as a necklace pendant or drop earrings.

Gemstones for Every Occasion

The gifts that mean the most are the ones that offer something personal, which is why gemstone jewelry is usually associated with special occasions or life events. Each gem has its own history and qualities full of symbolism. From birthdays to anniversaries, below are a few ideas for how gemstones can pair perfectly with some of life's biggest milestones.


Historically, birthstones were believed to have special powers when worn at certain times of year, specifically, during a certain month. The birthstone tradition has Biblical and philosophical origins, but now serves as a fun and individual way to personalize jewelry.

Anniversary Gemstones

Beyond engagement, many couples give gemstone jewelry or accessories to celebrate anniversaries. This modern take on gift-giving designates a specific gemstone for each anniversary instead of a certain material. Every anniversary year has a specific gemstone--take a look at the mile-marker anniversaries and their corresponding gems.

Gemstone Care

Close up of gemstone ring resting a a piece of ribbon

If you own gemstones, knowing how to care for them is crucial if you want them to last and maintain their sparkle. Building a care routine into your day-to-day schedule can help your jewelry stay beautiful and prevent future damage caused by neglect. Occasionally having your gemstone jewelry inspected by a professional provides the opportunity for an expert to catch and fix any problems or imperfections that require special attention and equipment.

Illustration of jewelry care

Daily Jewelry Care: Put on jewelry after applying makeup, hairspray, perfumes, lotions, and any other cosmetics to reduce your gemstones' exposure to chemicals.

Remove jewelry when performing tasks like gardening, cleaning, working on heavy equipment, or during exercise. This will prevent any physical damage and reduce the risk of exposing jewelry to chemicals and cleaning fluids. It's also a good idea to remove jewelry before entering the pool or spa. Chlorinated water can cause color changes and even structural damage to your gemstone jewelry.

Remove jewelry before bed and gently wipe items with a soft cloth to remove residues. It is best to store jewelry in a case where items don't touch each other. This prevents the harder gemstones or other hard jewelry pieces from scratching softer ones.

Illustration of jewelry storage

Jewelry Storage: When you aren't wearing your gemstone jewelry, avoid the temptation to toss jewelry into a drawer or on top of a dresser — that's a recipe for scratching, tarnishing, or misplacement. Jewelry should be stored away in a protective, lined jewelry box or a tarnish-resistant pouch. This protects items from sunlight and heat. Look for jewelry boxes that feature individual padded slots for rings, posts for earrings, and hooks for necklaces.

Illustration of jewelry cleaning

Jewelry Cleaning: Before cleaning your gemstone jewelry at home, consult a jeweler to get the best ideas for safe cleaning. Some gemstones require different cleaning processes than others. For example, many colored gemstones can't withstand the same type of rigorous cleaning that diamonds undergo. To clean your gemstone jewelry at home, pour a small amount of dish soap (no detergents) into a bowl of lukewarm water. Use a small, soft brush, like a toothbrush, to clean your jewelry, and then lay it on a towel to air dry. You can also use baking soda and water to remove tarnish, and polish gold with a mixture of baking soda and vinegar. Do this as needed. When regularly worn jewelry, such as wedding rings, becomes noticeably dull, it's always a good idea to take it to a professional jewelry cleaner. For the best results, get jewelry professionally cleaned every six months.