CARATS AND GEMSTONE SIZE

Carats are a unit of measurement used for gems. One carat equals 200 milligrams. Many people refer to thesize of a gem in terms of itscarats especially in regards to diamonds. However gems of the same size don't always weigh the same and gemstones gee in different shapes as well. For the purpose of geparison though listed below is a chart of the different sizesand shapes ofdiamonds and how many carats they arewhich can be used to approximate caratsfor other gems as well.
CARAT SIZE MILLIMETER WIDTH
Round shape
0.25.....................................4.1mm
0.50.....................................5.2mm
0.75.....................................5.9mm
1.00.....................................6.5mm
1.25.....................................7.0mm
1.50.....................................7.4mm
2.00.....................................8.2mm
2.50.....................................9.0mm
Oval shape
0.25.....................................5.0 x 3.0mm
0.40.....................................6.0 x 4.0mm
0.75.....................................7.0 x 5.0mm
1.00.....................................7.5 x 5.5mm
1.25.....................................8.0 x 6.0mm
1.50.....................................8.5 x 6.5mm
2.00.....................................9.5 x 7.5mm
3.00.....................................10.0 x 8.0mm
Marquise shape
0.25.....................................5.5 x 2.5mm
0.50.....................................8.0 x 4.0mm
0.75.....................................9.0 x 4.5mm
1.00.....................................10.0 x 4.75mm
1.25.....................................10.5 x 5.0mm
1.50.....................................11.0 x 5.0mm
2.00.....................................12.0 x 6.0mm
3.00.....................................14.0 x 7.0mm
Emerald Shape
0.25.....................................5.0 x 3.0mm
0.50.....................................6.0 x 4.0mm
0.75.....................................6.5 x 4.5mm
1.00.....................................7.0 x 5.0mm
1.50.....................................8.0 x 6.0mm
2.00.....................................8.5 x 6.5mm
3.00.....................................10.0 x 8.0mm
Princess shape
0.25.....................................3.4 x 3.4mm
0.50.....................................4.4 x 4.4mm
1.00.....................................5.5 x 5.5mm
1.50.....................................6.5 x 6.5mm
2.00....................................7.5 x 7.5mm
2.50....................................8.0 x 8.0mm
3.00....................................8.3 x 8.3mm4.40....................................9.0 x 9.0mm
Pear shape
0.20....................................4.0 x 2.0mm
0.50....................................6.0 x 4.0mm
0.75....................................7.0 x 5.0mm
1.0......................................8.0 x 5.5mm
1.5......................................9.0 x 6.0mm
2.0.....................................10.0 x 6.5mm
2.5.....................................11.0 x 7.0mm
3.0.....................................12.0 x 8.0mm
Trillion shape0.25..................................4.0 x 4.0mm0.50..................................5.0 x 5.0mm1.00..................................6.5 x 6.5mm1.50.................................7.0 x 7.0mm2.00..................................8.0 x 8.0mm3.00..................................9.0 x 9.0mm4.00................................10.0 x 10.0mm5.00................................11.0 x 11.0mm