Diamond Terms starting with the letter O |
| Octahedron
Any figure having eight sides or faces. In the case of a diamond, the diamond crystals that make a diamond are usually in the form of a Octahedron. |
| Off-Make, Off Make
Another term for a diamond that has a pretty poor cut. You'll notice right away usually by the lopsided effect in appearance the diamond may have. |
| Oiling
When a stone has many surface inclusions some may apply a process called Oiling. Which is a oil made of minerals that when rubbed on gem, typically not a diamond it can and usually will mask/hide the inclusion and bring out a more vivid color. |
| Old European Cut
A 58 faceted round diamond with a high crown and deep pavilion. It also has an open culet but this is not always the case. Not as popular today because today's version of a round cut let light pass though and up it a lot better that the days of the Old European Cut. |
| Old Miners Cut
Another old style form of the round brilliant cut. Often called the "Cushion Cut". It's characterized as having an overly large culet, very deep pavilion, and a rather small table. |
| One Carat
Equal to .2 grams, or 1/5th of a gram. One carat is the traditional size every diamond wants to be at or larger. The larger a diamond over the magical one carat range usually the more money it can command if all other of the 4C's are the same. |
| Opaque
Have you ever looked at a diamond and it appeared very milky, dull, or just has no sparkle. This is because the diamond is opaque, or non-transparent because light can not get back up to the top, or in some cases the light can't even penetrate the diamond at all. |
| Open culet
The culet is the bottom of the diamond, usually signified as a point at the bottom. An open culet is when the point has been changed to look more like a facet than a single point. |
| Orange
A very very very very rare color in a diamond. If you find one of these be prepared to really cash in especially if it's over a carat. |
| Oval Cut
A fancy shaped diamond cut, or "fancy cut" if you will. That is shaped in the shape of an oval. |
| Overtone
A second, not as strong, green, blue, or rose color in a pearl |
| Oxidation
The chemical reaction when a metal and oxygen are combined |
