He converted from Lutheranism to Catholicism. Blessed Nicholas Stenor is a man to be reckoned with both intellectually and spiritually. He was a geologist and discovered attributes of crystals as well.
Here is a note on his conversion: After making comparative theological studies, including reading the Church Fathers and by using his natural observational skills, he decided that Catholicism, rather than Lutheranism, provided more sustenance for his constant inquisitiveness. http://en.wikipedia.org/wiki/Nicolas_Steno
Google did a Google doodle for him two years ago.
Known as the father of stratigraphy and geology, Nicholas Steno worked to understand history by what he could find in the ground. Rather than simply write books about his findings, Steno opted to do his own hands-on research. As an innovative thinker, he disagreed with his contemporaries in thinking that shark-tooth-shaped objects found imbedded in rocks "fell from the sky." Instead, Steno argued that these formations were fossils. His dedication to analysis, critical thinking, and creative thinking make him a great subject for a Google doodle!
