Hand Tools Archive
Looking at my receipt, the part number matches the stick that's true rouge.
The feel of it having no cutting power at all gives it away.
Even though the other sticks have very tiny particles, you can *feel* them abrading the corian a tiny bit. Corian itself is really hard and musical feeling - it feels unforgiving.
Addition of wax and oil makes something that cuts very slowly (iron oxide powder used dry) unusable on steel.