Wash 7 half-pint canning jars. Keep hot until needed. Prepare 2-piece canning lids as manufacturer directs.
Measure out the sugar in a mixing bowl so it will be ready to add to the berries all at once when needed.
Mash the raspberries and blueberries in a large, non-aluminum pot and set aside.
Zest one orange and add the zest to the berries in the pot.
Peel the orange, discard the peel, and finely chop the orange pieces with a knife or in a food processor.
Measure 1/2 cup of the orange pulp and add it to the pot containing the mashed berries.
Add the powdered pectin and lemon juice to the pot, then bring to a boil, stirring frequently.
Add the pre-measured sugar all at once and continue to heat the mixture. Bring it to a full rolling boil over high heat, stirring constantly. Boil hard for one minute.
Ladle the hot jam into one hot jar at a time. Leave 1/4-inch head space in each jar.
Wipe jar rims with a clean, damp cloth. Attach lids.
Process in a boiling water canner for 10 minutes