An inclusion within a gemstone is an internal flaw, or included crystal, bubble, cloud, graining, fracture, etc. (shown in a peridot). Inclusions are different from blemishes, which are imperfections at the surface of the gemstone. Inclusions aren’t always bad.
I personally like to see some inclusions, it makes it feel more straight out of the mine and not all synthetic or heat-treated to enhance their color. Inclusions can be used like a finger print, to identify diamonds and other valuable gemstones. Carnelians tend to have some great inclusions that make each one individual, most take on a darker orange color.
Inclusions can often be used to tell the difference between natural and synthetic gemstones, and in some types of gemstones, the inclusion can even pinpoint the source of the natural stone. Like some aquamarines from Afghanistan have a completely different look from the general aquamarines you automatically think of. 
They have a darker hue to them and tend to have some yellow-brownish inclusions, which I think makes the blue pop even more!
In some cases, inclusions can actually increase the brilliance of a gemstone. Labradorite is one of them, and also one of my favorite gemstones.The color spectrum of the inclusion gives the stone a sort of 3D look. Its distinctive flash of iridescent colors is known as “labradorescence.” These beautiful flashes of color change according to the angle of light refraction, and may be somewhat metallic tints of blue, green, yellow, and pink, with the majority of the stone itself a dark grey in color. Here are a few great examples of the different colors labradorites can have.
So remember, that isn’t a chip or a crack in the stone, its a natural inclusion that is one of the most beautiful and natural processes in nature. For fun you should google search photos of gemstone inclusions. They are unbelievably amazing magnified! Check back soon for a post about color variations in stones.
Tags: aquamarine, blemishes, bubble, carnelian, flaw, fracture, gemstone, graining, imperfections, inclusion, jewelry designer, Judith Bright, labradorescence, labradorite, peridot, spectrolite
