Wash 6 small (1 cup) glass*** canning jars or plastic containers with lids. (If your jars are smaller, use more.) I like to put mine through the dishwasher. Dry thoroughly and set aside.
Peel, pit and thinly slice peaches into a large bowl. Add raspberries and mash everything with a potato masher. Don't mash it too fine, you want little pieces of fruit to remain.
Measure exactly*** 3 cups of fruit into a large microwave-safe bowl. (If you have extra, use on your morning yogurt or as an ice cream topping.)
Add sugar and lemon juice; mix well. Place bowl in microwave and heat on high power for 3 minutes. Remove carefully (as bowl will be hot) and stir for 3 minutes.
Take a little taste. If mixture is still a little grainy (sugar not dissolved) return to microwave for another 2 minutes, then stir well.
Mix water and pectin in small saucepan and stir to combine. Bring to boil on high heat, stirring constantly. Cook and stir for 1 minute. Add to peach mixture; stir for 3 minutes.
Fill all containers immediately to within ½ inch of tops. Wipe off top edges of containers; cover with lids. Let stand at room temperature 24 hours. Refrigerate up to 3 weeks or freeze up to 1 year. (If frozen, thaw in refrigerator before using.) Makes 6 cups of jam.