Add the cherries, sugar, rosemary, and lemon rind to a deep pot. Stir together until cherries are well coated with the sugar. Cover, and let the mixture sit at room temperature for about 1 1/2 hours, until it looks slightly thickened and the sugar has mostly dissolved.

Place the pot on the stove over medium-high heat. Bring it to a boil.

Using a slotted spoon, strain out the cherries into clean, sterilized glass jars (one pint jar or two ½ pint jars). Discard the lemon rind and rosemary.

Cook the remaining liquid in the pot for 1 to 2 minutes more, until it thickens slightly. Spoon the liquid over the cherries. Cover, and screw on the lid tightly. Process in a hot water bath for 10 minutes for long term storage. You can alternately let the conserves cool, and store them in the fridge for up to 1 month.