Types of Diamond Clarity Blemishes & Inclusions

Diamond Clarity shows the inside inclusions and outside surface marks of a stone. Every diamond has its own unique features formed during growth. If you often read diamond certificates, you will notice different internal and external flaws. Based on the GIA grading system, we explain all clarity features clearly. We divide them into two main parts: internal characteristics and external characteristics.

Internal Characteristics, also called Inclusions

These are flaws inside the diamond.

• Crystal: Tiny mineral crystals inside the stone. They look like dots or thin lines, black or white. Black crystals are more easy to see, and hurt clarity grade more.
• Feather: Internal cracks that look like feathers. Do not ignore its position. If the feather reach the surface, especially the girdle, hit may make crack bigger or even break the diamond. Small inner feathers are less risky.
• Cloud: Made of countless tiny dots. It looks like fog inside the diamond. Thick and large cloud will turn the stone hazy, people call it milk diamond. It greatly cut down shine and value.
• Pinpoint: Super small white dots. It is the mildest inclusion. Single pinpoint can not be seen by naked eyes. Many pinpoints together will form a cloud.
• Needle: Long and thin white crystal inside. It rarely affect clarity, unless it is too long or too many.
• Twinning Wisp: Lines or nets mixed with dots, clouds and crystals. It often appear in lab-grown diamonds. It is a weak structure. GIA report use red lines to mark it.
• Internal Graining: Irregular lines from crystal growth. Experts need magnifier to see it. Serious graining will reduce transparency.
• Cavity: Holes on the surface. It easily collect dirt and make the diamond less durable.
• Indented Natural: Slight dents of original diamond surface near the girdle. It is natural feature, not damage. It hardly affect looks.
• Knot: Crystal stretch to the surface. It is both internal and external flaw, and may weaken the stone.
• Bearding: Tiny feather cracks around the girdle. Light bearding can be fixed by re-polishing. Heavy ones ruin look and durability.
• Laser Drill Hole: Small holes made by laser to remove dark inclusions. This is a treatment. The hole is tiny and invisible to naked eyes. GIA will mark it on report.
• Chip: Shallow breaks on edges. It is damage, easy to catch dust and reduce sturdiness.

External Characteristics, also called Blemishes

These are surface flaws. Most of them can be removed by re-polishing.

• Natural: Original diamond surface near girdle. It is not a flaw, just natural mark.
• Abrasion: Small wear marks on edges from friction. Easy to fix with polish.
• Polish Lines: Fine parallel lines left during polishing. Good polish lines only show under 10x magnifier.
• Scratch: Thin lines on surface. Can be polished away.
• Pit: Tiny small holes on surface. It has little influence on clarity.
• Nick: Mini gaps on facet edges. Simple polish can fix it.
• Extra Facet: Extra cutting surface near girdle. It will not affect shine, only symmetry grade.

Clarity grade judge features under 10x magnifier, not the number of flaws. Our goal is to pick eye-clean diamonds.

First of all, stay away from milk diamonds and big cracks. Watch out for thick Cloud. Check if Feather run to the surface. Always trust official certificates like GIA or IGI. Their clarity diagrams tell you every flaw’s type and place.

For good value, VS1 and VS2 are great choose. Most inclusions can not be seen by eyes. Many SI1 diamonds are also eye-clean, you need to check carefully.

Seeing the real diamond is always best. Turn the stone under light. If it looks bright, clear and no dark spots or foggy look, it is a good diamond for you.