Paul;

"Relatively pure form" is a slippery phrase. But depending on the silver content of the hypo and the type of hypo solution, yes it can be 'relatively pure'. The other ingredients are iron and iron salts primarily. And the silver is rather unusable until it undergoes a rather lengthy repurification such as described by Ian. This involves dissolving it again, electrolysis and then dissolution in nitric acid and recrystallization.

PE