There are 4 Internationally recognised criteria for determining a diamonds price, referred to as the four C’s.
- Colour
- Clarity
- Cut
- Carat (Diamond Weight)
Colour
| Colourless | D | Finest White |
| E | ||
| F | Fine White | |
| Near Colourless | G | |
| H | White | |
| I | Commercial White | |
| J | Top Silver Cape | |
| Slightly Tinted | K | Silver Cape |
| L | ||
| M | Light Cape | |
| Very Light Yellow | N | |
| O | Cape | |
| P | ||
| Q | ||
| Light Yellow | R | |
| S | ||
| T | ||
| Yellow | U | Dark Cape |
| V |
Clarity
 |
IF | Internally Flawless | No visable inclusions under 10x magnification |
 |
VVS1, VVS2 | Very Very Slight Inclusions | Inclusions are extremely difficult to locate under 10x magnification |
 |
VS1, VS2 | Very Slight Inclusions | Inclusions are difficult to locate under 10x magnification |
 |
SI1, SI2 | Slight Inclusions | Inclusions are obvious under 10x magnification |
 |
I1, I2, I3 | Imperfect | Inclusions are obvious to the naked eye |
Cut
Round
 |
Princess
 |
Emerald
 |
Marquise
 |
Oval
 |
Pear
 |
Radiant
 |
Heart
 |
Carat
| 0.5ct | 0.75ct | 1.0ct | 1.5ct | 2.0ct |
|---|---|---|---|---|
 |
 |
 |
 |
 |
| 5.30mm diameter | 6.07mm diameter | 6.66mm diameter | 7.63mm diameter | 8.35mm diameter |