Gemma Frisius is a lunar impact crater that is located in the rugged southern highlands of the Moon.

[1] It lies to the north of the walled plain Maurolycus, and southeast of the smaller crater Poisson.

The outer wall of this crater has been heavily damaged by impacts, particularly along the north and west sides.

The remainder of the floor is relatively level and deep, with a central peak that is offset to the northwest of the midpoint.

By convention these features are identified on lunar maps by placing the letter on the side of the crater midpoint that is closest to Gemma Frisius.