Summarize this article in one sentence.
Use wire cutters to trim off a piece that’s long enough to wrap around the crystal and to form the ring, typically at least 2 feet (0.61 m). Err on the side of caution and cut a longer piece if you aren’t sure how much you’ll need. You can use a different size wire if you prefer, but pick a size that’s no thicker than 18 gauge and no thinner than 22 gauge for the best results. Take the 2 ends of the wire at the center where they intersect on the mandrel. Use a pair of needle-nose pliers to begin wrapping the wire in a small circle at the top of the ring where your crystal will sit. Continue twisting the pieces together until you have a circle that’s slightly wider than the ring band and lies flat.  It should take about 3 to 4 twists to create the circle. Don’t worry if your circle isn’t a perfect spiral. The crystal will cover it so it won’t be visible. Try to leave about 3 to 4 inches (7.6 to 10.2 cm) of wire at the ends after you’ve twisted the circle. Slide the ring off of the mandrel once you've wrapped the circle at the top. Be careful not to squish or bend the band of the ring while removing it. If the ring doesn't slide off easily, gently wiggle it back and forth as you pull it up the mandrel to loosen it. Set the crystal in the position that you want it to be on the ring. For example, if you have a long piece of quartz, decide if you want it to lay so that it goes down the length of your finger or across the width of your finger. Align the crystal so that it completely covers the wire circle underneath unless you want the base to show. Because you originally made the ring a smaller size, you may need to enlarge it slightly to fit your finger. To do this, slide the band onto the mandrel. Then take a hammer and lightly tap the top side of the band to loosen the metal. As it becomes pliable, slide the ring down the mandrel until it's at the correct size groove.  For instance, if you wear a size 8 but made your ring a size 7, hammer the band until it reaches the size 8 groove. Alternate hammering the band and sliding it down the mandrel.

Summary:
Cut a piece of 20-gauge wire that’s about 2 feet (0.61 m) long. Twist the wires clockwise at the top of the ring to create a base for the crystal. Remove the ring from the mandrel. Place the crystal on top of the circle base. Size up the ring by placing it back on the mandrel and hammering the band.