Perhaps the most well-known of the imperfect Misfit Diamonds, “Salt & Pepper” refers to diamonds with many inclusions, such as feathers, clouds, or other minerals, with a black and white (or colorless) appearance like salt and pepper.

“Rust” or “Rustic” are terms used to describe a diamond with rust-colored inclusions, typically caused by the presence of iron.

A star-like pattern that occurs in diamonds when dark inclusions (usually hydrogen clouds) align with the crystal axis; most well-know for occurring in emeralds, trapiche patterns in diamonds are quite rare.

An indented triangle that appears naturally on the surface of a diamond crystal during the growth process; trigons can appear solitary or in groups, sometimes stacking within larger trigons.

Black inclusions that appear in diamonds are often referred to as “carbon spots”; however, they are rarely carbon, but other black minerals usually pertaining to the amphibole or pyroxene groups (which are really just fancy words for other rocks).

An area on the surface of a polished diamond that has intentionally been left unpolished in the cutting process, often to leave some unique feature that appeared on the rough crystal surface (such as a trigon), usually appearing near or on the girdle; an indented natural is a natural that extends inward, distinct from a chip.

An indented opening where a crystal broke away or a feather opened up, usually the result of polishing.

A cluster of microscopic crystals or pinpoint inclusions can cause a hazy looking “cloud” inclusion.

A feather is an internal fracture in a diamond (or sapphire), often with a feathery appearance (hence the name); feathers can often cause a rainbow to appear inside a gemstone because of light travelling through trapped air and causing dispersion.

A needle-like mineral inclusion, often the mineral rutile (pictured).

Inclusions in gemstones are often other gemstone crystals; for example, diamonds may have garnet, peridot or zircon crystals - or even other diamonds.

A wispy line of microscopic inclusions, either pinpoints or clouds, inside a diamond caused by irregular crystal growth.

A crystal inclusion that reaches the faceted surface of the diamond.

A microscopic crystal inclusion that appears only as a pinpoint through a jeweler’s loupe.

Despite their hardness (diamonds = 10, sapphires = 9 on Moh’s scale of hardness), enough impact can cause a diamond to break. Terms like “chip,” “abrasion” or “fracture” imply damage to a stone, while indented naturals and cavities occur naturally.

Not so much an inclusion, naturally occurring diamond colors are caused by the presence of specific elements, radiation or imperfections in the crystal structure.

Fancy White color in diamonds is caused by a high concentration of microscopic cloud-like inclusions.

Fancy Grey color in diamonds is caused by the presence of hydrogen (and sometimes boron).

Fancy Black color happens when a diamond has so many black inclusions causing it to be nearly or entirely opaque; black color is sometimes enhanced using irradiation. (Any treatments are disclosed in the product listing.)

A mineral inclusion common in sapphires that forms as long needles; many parallel rutile needles have a "silk" appearance, often creating a sheen or opalescence, and the reason for asterism in sapphires.

Occurs in sapphires when healing happens during formation, a liquid-like inclusion resembling a fingerprint.

In heated sapphires, a zircon halo occurs when a zircon crystal inclusion bursts during the heating process, resembling a small, clear disc-like inclusion.

Inclusions in gemstones are often other gemstone crystal, such as: hematite, calcite, mica, spinel or zircon.

An internal fracture inside a gemstone, often with a feathery appearance (hence the name).

Areas of different color within a sapphire, often appearing along the hexagonal growth lines, or as distinct areas of color like in parti-color sapphires.

Two or more distinct colors within the same stone; sometimes referred to as bi-color sapphires (when only two colors).

Because sapphire crystals form as hexagonal prisms, hexagonal growth lines will often appear within a stone, as color zoning or with rutile forming along the crystal axes.

Typically caused when microscopic rutile silk inclusions cause the light to scatter, giving some sapphires an appearance like an internal glow.

The optical phenomenon found in star sapphires, occurring when dense rutile inclusions cause the light to reflect a six-star pattern.