A group of tiny pinpoints found inside a diamond. Most clouds are made up of crystals too tiny to see individually under the 10X magnification of a jeweler's loupe. Clouds may be impossible to see with the naked-eye in diamonds of very high clarity. This is rarely a serious inclusion.
Jewelry Glossary
Cloud
More terms starting with C
Keep learning
Our education centre covers diamonds, precious metals, gemstones, and how to choose a ring in far more depth than a definition allows.