I made this for X-mas presents last year - big HIT!
RASSBERRY, CRANBERRY AND PINK GRAPEFRUIT JAM

2 pink or ruby red grapefruit, halved
1 1/2 cups sugar
6 cups frozen unsweetened rassberries (about 1 1/2 pounds), unthawed
1 12-ounce bag fresh or frozen cranberries
Canning jars

Squeeze juice from grapefruit. Measure 1 cup juice, discarding seeds; place juice in heavy large saucepan. Add sugar to juice. Mix in 4 cups rassberries and all cranberries. Spoon 2 cups rassberries into medium bowl; let thaw at room temperature. Let berry mixture stand until berries thaw and sugar dissolves, stirring occasionally, about 1 hour.

Bring mixture to boil over high heat. Reduce heat to medium. Boil gently until mixture thickens and liquid drops thickly off end of spoon, stirring often, about 25 minutes. Mix in 2 cups thawed rassberries with any juices; bring to boil.
(now for the part that I'm sure you all know but... behr)
Spoon preserves into hot canning jar, filling only to 1/4 inch from top. Immediately wipe rim, using towel dipped into hot water. Place lid on jar; seal tightly. Repeat with remaining jars and preserves.

Place jars on rack in large pot. Add boiling water to pot so that at least 1 inch of water covers tops of jars. Cover pot; boil rapidly 15 minutes. Remove jars. Cool completely. Press center of each lid.
If lid stays down, jar is sealed. (If lid pops up, store preserves in refrigerator.) Store in cool dry
place up to 1 year. Chill after opening.

Makes about 4 generous cups

(Origin - Bon AppÈtit December 1995 with a few alt. by me)