Complex sentence: The pebble was purchased from Jacobs by Schalk van Niekerk, who later sold it, and turned out to be a 21.25 carat (4.25 g) diamond, known as the Eureka.
Split into simpler sentences: The pebble was purchased from Jacobs by Schalk van Niekerk, who later sold it. It proved to be a 21.25 carat (4.25 g) diamond, and became known as the Eureka.