Robbinroger Beever was 15 years old and walking home along a beach in Liberia, West Africa.The year was 1967. Beever’s family lived near Monrovia, where his diplomat father worked at the U.S. Embassy.It was high tide and the sea had washed up seaweed and planks of wood and strewn them across the beach. Amid the debris, Beever spotted something glistening in the late afternoon sun.”I’m