G : G is the seventh letter of the English alphabet, and a vocal consonant. It has two sounds; one simple, as in gave, go, gull; the other compound (like that of j), as in gem, gin, dingy. See Guide to Pronunciation, // 231-6, 155, 176, 178, 179, 196, 211, 246.

G : G is the name of the fifth tone of the natural or model scale; -- called also sol by the Italians and French. It was also originally used as the treble clef, and has gradually changed into the character represented in the margin. See Clef. G/ (G sharp) is a tone intermediate between G and A.

Example:
What volume does a 56.2-G sample of neon Gas occupy at these conditions of temperature and pressure?

Taxonomy
Gemological Institute of America, How to, gemstone, gemology research, Education, laboratory services, 4Cs, a Diamond, diamond value, Distance Education, diamond grading, jewelry education, latest version, the Adobe, simple steps, Distance Learning, best of both worlds, at-home.

Defination from the web:
Working to ensure the public trust by educating and serving the gem and jewelry industry worldwide.