What's the difference between petrography and petrology?

Petrography

Definition:

• (n.) The art of writing on stone.
• (n.) The scientific description of rocks; that department of science which investigates the constitution of rocks; petrology.

Example Sentences:

• (1) It can also be used for many other applications, for example, in metallurgy, petrography and geostrategy.

Petrology

Definition:

• (n.) The department of science which is concerned with the mineralogical and chemical composition of rocks, and with their classification: lithology.
• (n.) A treatise on petrology.

Example Sentences: