Combine blueberries, sugar, lime juice, and lime zest in a medium saucepot. Bring mixture to boil over medium-high heat. Once mixture has come to a boil, reduce heat to medium.
Place a couple metal spoons in the freezer while you cook the jam. Let the jam cook for 15-25 minutes until the blueberries have broken down and the mixture has thickened.
To test for doneness, dip frozen spoon into hot jam mixture. The jam should fall off the spoon slowly in one thickened mass. If it does not, continue to heat the jam for another 5 minutes before testing again.
Transfer cooked jam into glass jars with tight fitting lids. Let the jam cool uncovered to room temperature. Then cover and keep jam in refrigerator for up to two weeks.