I found some very interesting information on both S. 'Oddity' and S. 'Grigg's Surprise'.
Both are considered to be what is called a "quilled' type sempervivum:
Grigg's Surprise is a var. from Europe and is considered to be a mutation. No history on what semp it mutated from. It has grey/green leaves that are hollow tubes
without an opening at the tip. Each leaf ends in a red, thorn like tip that is often double, like an open bird's beak. The leaves are minutely hairy, especially near the tip.
This is according to the writings of Helen Payne in here wonderful book 'Plant Jewels of the High Country'. She goes on to say that it take a very good eye or magnifying glass to see the intricate details.
Oddity is a mutation from S. albidum. Green with deep purple tips. Base leaves are curled under. The rest of the leaves are tube-like and open at the end like the lower part of a feather.
We should have a much easier time now knowing which of the two plants we are looking at.
Oddity with open quilled ends--------------------Grigg's Surprise with hairy leaves and closed quilled ends.
