Choosing from gold, silver, or bronze effectively does this. It groups them by type and puts a check mark next to those you've earned.
Having said that, if this level of detail is desired, providing filters would accomplish what you want.
When bringing up the badge list, a list of filters could be shown:
[x]Earned [x]Unearned [x]Gold [x]Silver [x]Bronze
You could then select and deselect individual filters as you wished.