The geology around Bancroft is rich in mineral pegmatites, as a result of molten lava being trapped under the Canadian Shield one billion areas ago.
The geology of Bancroft is noted for having bodies of quartz surrounded by rare earth minerals, including zircon and uraninite.
[1] The Gemboree was started on 1963[2] by two dozen people based out of a tent and a room at the local Royal Canadian Legion.
[2] By 1991, the event was being held at the Bancroft's North Hastings Community Centre and The Globe and Mail reported that it was described as "the largest show of its kind in Canada.
"[3] The 1995 Gemboree attracted mineral vendors from across Canada, the US and South Africa.