“...In the early to mid-1990s a source of fabulous red/white/grey agates, some with smoky quartz or amethyst centers, was discovered in Ardownie Quarry. For a few years collectors could find beautiful agates and geodes up to 300 mm there, but the source rock is now high in the quarry wall and inaccessible. Similar agates were also found in the nearby Ethiebeaton Quarry, but that location is also inaccessible now...”

according to personal communication with Alexander Cooper