Here are two crosses that I have done from old dishes. I have a friend who has an antique shop and she would save the broken and chipped dishes for me that she would get along with the good pieces. I love using the damaged pieces as it gives new life to pieces that would other wise be thrown away.
Franciscan Apple Cross
This cross was made from the Franciscan Apple pattern. It is a small cross. It measures 3" x 8". I cut the cross piece which was the edge of small plate with my ring saw. Some of the other pieces were cut with the ring saw. Others were just nipped. The pieces were glued on a wooden base. The piece was then grouted and the base was painted a brown that matches the brown on the tesserae. The grout and the painted base were then sealed.
Blue Onion Cross
The Blue Onion cross is made from small plates with a Blue Onion pattern. I don't think that these plates were vintage Blue Onion, but were newer dishes. The cross measures 7" x 3 3/4". The base is wooden. The tesserae was all nipped and glued onto the wooden base. The piece was then grouted and the base was painted a dark blue to match the blue on the tesserae. The grout and the blue paint were both sealed.
Both of these crosses can be purchased at my shop, Jack Rabbit Flats on Etsy.