Diamond inclusion are flaws inside of a diamond or other gemstone

Diamond inclusions are characteristics that occur inside the gemstone. They are usually called flaws, because their presence means the diamond is not perfect.
Inclusions are like fingerprints, a characteristic that gives us all a special signature. Getting to know your diamond inside and out makes the stone a more personal possession—and will help you describe and identify the gem if it is ever lost or stolen.

Some inclusions affect a diamond's clarity, making it less brilliant because they interfere with light as it passes through the stone. Other types of inclusions can make a diamond more vulnerable to shattering.

There are few perfect diamonds, and the ones that are perfect are quite expensive, so the diamonds we buy all have varying amounts of internal and external flaws. Most jewelers tell us not to worry about diamond inclusions if they do not affect the stone's strength or seriously impact its appearance.

Types of Diamond Inclusions

Crystals and Mineral Inclusions
Diamonds can have tiny crystals and minerals embedded in them, even other diamonds. Many cannot be seen without magnification, but a large chunk or grouping of crystals that detracts from a diamond's appearance lowers its clarity grade, and its value.

There are times that a small crystal can add character to a diamond. A diamond with a tiny garnet inside would be a conversation piece -- and a nice personal choice for someone whose birthstone is a garnet.

Pinpoint Inclusions

Pinpoints are tiny light or dark crystals in diamonds and other gemstones that can either appear by themselves or in clusters. Larger clusters of minute pinpoints can create a hazy area in the diamond, called a cloud, which affects the diamond's clarity.

Laser Lines

Laser lines are not a natural diamond inclusion. These vapor-like trails are left behind when lasers are used to remove dark inclusions from the diamond. The machine-made trails look like tiny strands of thread that begin at the diamond's surface and stretch inward, stopping at the point where the inclusion was removed.

Feathers

Feathers are cracks within the diamond that resemble, well... feathers. Small feathers do not usually affect a diamond's durability unless they reach the surface on the top of the stone, a location that's prone to accidental blows.

Cleavage

Diamond cleavage is a straight crack with no feathering. A cleavage has the potential to split the diamond apart along its length if it is hit at the correct angle.

Small cracks that are not visible when a diamond is viewed in a table-up (face up) position do not seriously affect clarity ratings.

Girdle Fringes, Bearding

Girdle fringes, or bearding, are hair-like lines that can occur around the girdle during the cutting process. Minimal bearding is usually not a problem, but extensive fringing is often polished away or removed by re-cutting the diamond.

Grain Lines, Growth Lines

Grain lines are created by irregular crystallization that takes place when a diamond is formed. Colorless grain lines do not usually affect diamond clarity unless they are present in large masses. White or colored grain lines can lower a diamond's clarity grade.

Always shop for diamonds at a jewelry store you trust and find someone who can answer your questions about the diamonds you are considering. Ask the jeweler to show you each diamond under magnification and explain its characteristics to you.

Why are most minerals not popular as gems?

A gemstone or gem (also called a precious or semi-precious stone, or jewel) is a piece of mineral, which, in cut and polished form, is used to make jewelry or other adornments. However certain rocks, (such as lapis lazuli) and organic materials (such as amber or jet) are not minerals, but are still used for jewelry, and are therefore often considered to be gemstones as well. Most gemstones are hard, but some soft minerals are used in jewelry because of their lustre or other physical properties that have aesthetic value. Rarity is another characteristic that lends value to a gemstone. Apart from jewelry, from earliest antiquity until the 19th century engraved gems and hardstone carvings such as cups were major luxury art forms; the carvings of Carl Fabergé were the last significant works in this tradition.

There are millions of minerals that exist on the earth, but few of them are prized as gems and used for adornment. Many of them aren’t in colors that are usually highly prized for jewelry. Or they’re not able to be cut and polished to be made wearable as jewelry.

Often it’s a matter of changing taste and times. In Imperial Russia and in the Victorian era, the mineral malachite and other opaque minerals were highly valued as gemstones jewelry. It is often a by-product of copper mining, and is distinguished by a brilliant green color, with dark concentric circles of color swirling through it. It’s not as highly valued because it’s easily available and not as expensive as an emerald or ruby. But there is an entire room devoted to malachite in the Russian museum, the Hermitage, as testament to its desirability among the most privileged class of people.

There have been discoveries that indicate that malachite was mined in Egypt as early as 4,000 B.C. It’s a soft gem, and easily carved and shaped. It polishes to a beautiful, rich sheen. But still is not highly prized in the U.S. as a gemstone.

Very often some minerals simply shouldn’t be used as gemstones, but because of their beauty, people wear them as such anyway. A moonstone is one such gem. It’s relatively soft, with a rating of 6 on Moh’s scale of mineral hardness, compared to a diamond’s hardness rating of 10. It’s a type of mineral called orthoclase, but when it exhibits a translucent, milky quality, it’s then called moonstone.

Other minerals exist, but are simply not prized for gemstones. Among the more common minerals, quartz stands out as one that can be used for jewelry, as well as decorative items.