Glossary - D
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- Depth
- The height of a gemstone measured from the culet to the table. For more information, read our education on diamond cut.

- Design
- The decisions made while crafting a diamond which determine its shape, including its weight ratio and durability. This is a component of the cut grade, as determined by the GIA.
- Diameter
- The width of a loose diamond, earring, pendant, or any round part of a piece of jewelry as measured across the widest part. This measurement is an estimated average. For more information on diamond diameter, read our education on diamonds.
- Diamond
- Diamonds are formed naturally when carbon is exposed to intense heat and pressure. Diamond is the hardest naturally-occurring substance on Earth, meaning that it is most resistant to scratching.
- Diamond Dossier®
- The Diamond Dossier is a special GIA report issued for diamonds weighing less than 1 carat. It features a laser inscription, but no diamond plot.
- Dimensions
- The length and width of a gemstone as it appears from the top when set in jewelry. This measurement represents the size of the gemstone more accurately than carat weight.
- Dispersion
- The term used to describe how white light is broken into its spectral (rainbow) colors.
- Drop Earrings
- An earring that hangs below the ear lobe, usually features dangling precious metal, diamonds, or gemstones.
- Drop Necklace
- A necklace that features precious metal or gemstones dangling from a chain.