D is the abbreviation of diamond, which means diamond.

In 0 13ct, ct is the abbreviation of carat, and 0 13ct means 0. 13ct, that is, the weight of diamond is 0. 13ct, 1ct = 100, and the diamond is/kloc.

Carat (Ct) is the unit of mass (weight) of gemstones. Now 1 carat is equal to 0.2g or 200mg .. One carat is divided into 100 minute, such as 50 minutes or 0.5 carat, which is used to calculate smaller gemstones. Because the density of gems is basically the same, the heavier the gem, the bigger the volume. The bigger the gem, the rarer it is, and the higher the value per carat.

Carats, or carats and carats, have been used since 1907, when they were internationally recognized units of measurement for gems. It is the quality unit of jade beads, diamonds and other precious stones, and the purity ratio of precious metals.