Gemology vs. Geology — What's the Difference?

Gemology or gemmology is the science dealing with natural and artificial gemstone materials. It is a geoscience and a branch of mineralogy.

Geology (from the Ancient Greek γῆ, gē ("earth") and -λoγία, -logia, ("study of", "discourse")) is a branch of Earth science concerned with the solid Earth, the rocks of which it is composed, and the processes by which they change over time. Geology can also include the study of the solid features of any terrestrial planet or natural satellite such as Mars or the Moon.

The study of gems.

The science which deals with the physical structure and substance of the earth, their history, and the processes which act on them.

The art and science of gems.

The scientific study of the origin, history, and structure of the earth.

The structure of a specific region of the earth's crust.

A book on geology.

The scientific study of the origin, history, and structure of the solid matter of a celestial body.

The science that studies the structure of the earth (or other planets), together with its origin and development, especially by examination of its rocks.

The geological structure of a region.

The science which treats: (a) Of the structure and mineral constitution of the globe; structural geology. (b) Of its history as regards rocks, minerals, rivers, valleys, mountains, climates, life, etc.; historical geology. (c) Of the causes and methods by which its structure, features, changes, and conditions have been produced; dynamical geology. See Chart of The Geological Series.

A treatise on the science.

A science that deals with the history of the earth as recorded in rocks