Isobel won the 8-12 year-old new media section of the 'Rock star' competition organised by Rockwatch, a national club for all young fans of Fossils, Rocks and Minerals.
Isobel was in Year Six at Pebsham Community Primary School when she was entered into the competition.
She produced a 16-page power-point covering the different types of rocks and also looked at birthstones, both traditional and modern.
Now at Bexhill High School, Isobel was given the day off on Friday to travel up to London for the prize-giving.
The event took place at the head offices of Anglo American, a mineral exploration company and one of Rockwatch's major sponsors.
The day started with a talk about the different types of jobs a geologist can do, based around a fascinating talk about life as an exploration geologist and their travels all around the World.
This was followed by the prize-giving ceremony when the winners were presented with certificates and prizes that included books, mineral collections and fossils from Chris Carlon of Anglo American Exploration Division and Susan Brown, chairman of Rockwatch.