Oh wow — in crystals with certain type of defects they call their dual behavior not slip-stick but slipping or twinning — and there is a slip-twin/twin-slip state in the middle. Might be deeper than I’m ready for — irregular crystals you twist and it can go from slipping past itself to deforming permanently … a little over my head. Something to do with angles. But I’ll have a placemarker knowing there’s a “1D” stick-slip possible, at least they call it 1D although I see more than that but i get what they mean.
yeah my brain isn’t ready for this. I’ll step back to slip-stick but it’s good to know one’s boundary conditions.