Memorial's solemn quality around Sabbath (10)
I believe the answer is:
gravestone
'memorial's' is the definition.
(I've seen this before)
'solemn quality around sabbath' is the wordplay.
'solemn' becomes 'grave' ('grave' can be a synonym of 'solemn').
'quality' becomes 'tone' ('tone' can be a synonym of 'quality').
'around' means one lot of letters goes inside another.
'sabbath' becomes 's'.
'grave'+'tone'='gravetone'
'gravetone' enclosing 's' is 'GRAVESTONE'.
(Other definitions for gravestone that I've seen before include "lapidary valediction" , "Churchyard memorial" , "Burial marker" , "superior to body" .)