i have got some small bits of gold(ish) items,
two of which have a 22kt stamped on the back of them,
which i assume are an indication to their gold purity.
however i have never come across
this 22kt mark

SO ... is there ANY test I can do at home:

like heating the gold up?
scraping it to see if it is a different color?
or
anything else

thanks in advance