Agates are abundant in the hills along the north shore of Kamloops Lake from Tranquille River to Carabine Creek. Some nodular forms are geodes with amethyst-lined central cavities. Banded and plain agate (chalcedony) occur as vesicle fillings, irregular masses and as ribbons of seam agate filling fractures and spaces in brecciated volcanic flows of the Eocene Kamloops Group. In places, the agate has a pink cast but the usual colours are white to grey. Agate is also reported upstream in the banks and stream bed of Tranquille River.