Taken from here
“Thus identified with astronomy, in proclaiming truths supposed to be hostile to Scripture, Geology has been denounced as the enemy of religion. The twin sisters of terrestrial and celestial physics have thus been joint-heirs of intolerance and persecution—unresisting victims in the crusade which ignorance and fanaticism are ever waging against science. When great truths are driven to make an appeal to reason, knowledge becomes criminal, and philosophers martyrs. Truth, however, like all moral powers, can neither be checked nor extinguished. When compressed, it but reacts the more. It crushes where it cannot expand—it burns where it is not allowed to shine. Human when originally divulged, it becomes divine when finally established. At first, the breath of a rage—at last it is the edict of a god. Endowed with such vital energy, astronomical truth has cut its way through the thick darkness of superstitious times, and, cheered by its conquests, Geology will find the same open path when it has triumphed over the less formidable obstacles of a civilized age.”
Sir David Brewster More Worlds than One: The Creed of the Philosopher and the Hope of the Christian (1854), 42.
While not technically a geologist, David Brewster can be considered one of the most important figures in advancing our understanding of mineralogy. Most of his work centered around the diffraction of light and it’s uses in optical mineralogy in regards to crystal structure, symmetry, and refraction interference colors. He’s also the inventor of the kaleidoscope (1).