| Thin? Thick? Which do I prefer? | | | | shallow, if the Table is large, and the Girdle is thick |
| When looking at details of a diamond, either on | | | | and not polished. Combinations of these factors |
| the certificate or just what is listed on a diamond | | | | worsen the effect. |
| website, you will notice that one of the | | | | The best diamond girdle thickness is Thin, Medium |
| parameters is called "Girdle" and the options of | | | | or Slightly Thick. Rarely will the measurement be |
| what it might be measured at are: Thin, Thick, | | | | a straightforward "Thin" or "Thick". More common |
| Medium and variations of those three. | | | | is when it is a combination of the sizes - "Thin to |
| What is the girdle, and what does the | | | | Slightly Thick", "Medium to Extremely Thick", etc. |
| measurement mean? | | | | Sometimes there might remain some small thinner |
| The Girdle is the flat edge on the circumference | | | | areas that may include parts of the original rough |
| along the edge of the diamond. It is the section of | | | | diamond material. As long as they are on the |
| diamond between the Crown above and the | | | | upper part of the Pavilion, these remnants will not |
| Pavilion below. The measurement of the Girdle is | | | | affect the diamond. This will usually be marked on |
| quoted in either words (Thin, Thick etc) or as a | | | | the diamond certificate as "Naturals". |
| percentage of the diameter (e.g. thin =.6% or | | | | If the Girdle is Extremely Thin or Very Thin |
| thick = 3.0%). | | | | areas, it is best not set them in exposed areas in |
| The Girdle is formed by a process called Bruting. | | | | rings; thin parts can be cleaved or chipped. These |
| Bruting, as Wikipedia explains, "is the process | | | | stones are OK in pendants and earrings, but there |
| whereby two diamonds are set onto spinning | | | | is still a very slight risk of chipping during the |
| axles turning in opposite directions, which are then | | | | setting of the diamond. Be careful when selecting |
| set to grind against each other to shape each | | | | diamonds that have pointy ends with Extremely, |
| diamond into a round shape. This can also be | | | | Very Thin, or even Thin parts on the points - |
| known as girdling". | | | | there is a high risk of damage during prong setting |
| Bruting is basically the process of grinding two | | | | on such stones. |
| diamonds against each other on a machine called a | | | | Diamonds with Thick, Very Thick, or Extremely |
| lathe that results in a ground glass like finish. When | | | | Thick girdles weigh considerably more, so the |
| Girdling a diamond, one can finish it by creating a | | | | spread of a diamond is reduced. But thicker girdles |
| faceted Girdle, by polishing the Girdle to a smooth | | | | have little impact on a diamond's sparkle. If a |
| and shiny surface, or by leaving it unfinished and | | | | diamond has an Extremely Thick Girdle, one must |
| dull. | | | | be careful to ensure that it was not left |
| Most larger diamonds today have faceted girdles - | | | | Extremely Thick for the sole purpose of adding |
| a faceted Girdle will generally have nearly 100 tiny | | | | weight to the diamond. There is no benefit to the |
| facets! | | | | added weight when it is in the Girdle. |
| A bruted girdle does not lower a diamonds grade, | | | | If, for example, the diamond is just over a price |
| as it does not affect the appearance or quality of | | | | threshold, such as it is 1.00 or 1.01 Carat, and is |
| the diamond. The only time the Girdle might | | | | listed as having a Girdle that is Extremely Thick, |
| affect the diamond in any way, either appearance | | | | you should consider that the cutter bruted the |
| or price, is if the stone is a 'fish-eye diamond'. | | | | diamond with that size Girdle for the sole purpose |
| A fish-eye is a nasty appearance that you can | | | | of getting the diamond over the weight of 1.00 |
| see inside the Table of the diamond. It looks | | | | Carat. Had he left it as a Medium or Thin, perhaps |
| slightly crazed and dull, just like a dead fish's eye. | | | | it would have weighed.98 or even less, thus |
| The fish-eye is a reflection of the girdle. If the | | | | costing you less. |
| girdle is not polished and is thick, the effect looks | | | | You do not want to pay more for a 1 Carat |
| like a large rounded inclusion. | | | | diamond just because of the added weight of the |
| Fish-eyes are more apparent if the Pavilion is | | | | Girdle. |