Teams played around your old stone (8)
I believe the answer is:
amethyst
'stone' is the definition.
(I've seen this before)
'teams played around your old' is the wordplay.
'played' is an anagram indicator (letters playing around).
'around' is an insertion indicator.
'your old' becomes 'thy' ('thy' historically meant 'your').
'teams' anagrammed gives 'amest'.
'amest' placed around 'thy' is 'AMETHYST'.
(Other definitions for amethyst that I've seen before include "One showing sparkling facets" , "Bluish-violet 3" , "Purple gem" , "Purplish gemstone" , "Transparent bluish quartz" .)