Kunz was born in New York City, USA, and began an interest in minerals at a very young age. By his teens, he had amassed a collection of over four thousand items, which he sold for four hundred dollars to the University of Minnesota. Kunz attended Cooper Union but did not finish and did not attend college. Nonetheless, he taught himself mineralogy from books and field research. This expertise landed him a job with Tiffany & Co., and his knowledge and enthusiasm propelled him into a vice presidency by the time he was 23. He gained much notoriety for identifying a new gem variety of the mineral spodumene which was named "Kunzite" in his honor.