The rosettes are rich purple at the centres in contrast to the blue-green leaf tips. The centres remain dark in summer but the tips and outer leaves become lighter with a touch of yellow. Uncommon in the UK.
A variety that is nearly 60 years old and still worth growing - and it was raised by someone who became an eminent expert in Sempervivum. He named it after a volcanic crater near his home - perhaps it was he who started naming Semps after volcanoes?