In 1826 he retired from the college and devoted his attention exclusively to geology as a profession.

During that year he published in newspapers and in Robert Mills' "Statistics of South Carolina" report on the geology of the state.

Professor Vanuxem's private collection of mineral and geological specimens was considered at the time of his death to be "the largest, best arranged, and most valuable private collection in the country."

[1] Vanuxem saw the need for a uniform system of nomenclature in the United States which led him to form a collaborative group that in 1847 became the American Association for the Advancement of Science.

Raised in the Presbyterian Church, he abstained from alcohol and tobacco and was a strong advocate of human rights.