1. of or relating to petrography, the branch of geology that describes and classifies rocks
Usage: technical; geology

Examples

• The petrographical analysis revealed the mineral composition of the ancient lava flow.
• Petrographical studies help geologists understand the formation history of rock samples.
• The museum's petrographical collection includes thin sections of rocks from around the world.
• Petrographical examination under a microscope showed the crystalline structure of the granite.
• The research team used petrographical methods to classify the newly discovered rock formations.