Soak store-bought oranges for an hour and scrub to remove any food grade wax. Strip the peel from the oranges using a vegetable peeler and remove as much pith as possible. Cut orange peel onto strips. Remove as much of the white pith from the oranges as possible.
Using a sharp knife cut a small slice off each end of the orange. Cut in between the membrane of each slice of orange discarding the membrane pieces and reserving the orange segments. Chop the orange segments to measure 1½ cups of fruit and juice. Prepare the peaches by peeling, pitting and chopping.
Place all of the ingredients into an uncovered 8-quart pot. Bring to a boil occasionally stirring until the sugar dissolves Cook at a low boil for 45 to 50 minutes. Remove from heat, skim foam if needed. Fill hot jars leaving a ¼ headspace. Wipe the jar rims and place lids on and screw on a band fingertip tight.
Place the filled jars into the hot water bath canner. Process the Peach Orange Marmalade for 10 minutes. Turn the heat off, remove the canner lid and allow to cool 5 minutes. Remove jars from the canner and allow to cool on a dry towel overnight before labeling with my free marmalade labels and storing.