Cognomen เพชรแก้ว (Diamond 
, Phetkaew 
, เพชรแก้ว) , all around the world, is a common surname. The surname เพชรแก้ว is habitual in Saint Kitts and Nevis, where it is quite a common surname, Saint Vincent and the Grenadines, and Jersey (explore the name in all countries). In absolute terms, this name is the most popular in the United States, Nigeria, and the United Kingdom. Also, เพชรแก้ว is the forename as well as the last name.
| VARIANT | COUNTRY |
|---|---|
| Diamond | Indonesia, United Kingdom, Nigeria, United States, Myanmar |
| Phetkaew | Laos, Thailand |
| Pechkaew | Thailand |
Pechkaeo, Pechtakuaw, Pecthkeaw, Pectkaew, Pehtkaew, Petchakaeo, Petchakaew, Petcharakeaw, Petchaykeaw, Petchkaeo, Petchkaew, Petchkaw, Petchkeao, Petchkeaw, Petchkeow, Petchkwaew, Petckaew, Petckhaew, Pethkaew, Petkaemkaew, Petkaeo, Petkaew, Petkawkeaw, Petkeao, Petkhoakiaw, Petlcaew, Pettkaew, Pettkeaw, Pheachkaew, Phedkaew, Phekkaw, Phetaemkaeo, Phetgaew, Phetkaemkeaw, Phetkaeo, Phetkeao, Phetkeaw, Phetkeow, Phetkew, Phetrkaeo, Phetrkaew, Pheykaeo, Phretkaew, and Phtekaew