This cross hangs at Exchange Community Church in Winnipeg and was completed while I was pastoring there. I invited the members of the congregation to bring something from their junk drawer or wherever to add to the mosaic. I also invited members to assist in assembling, grouting, cleaning etc, so that it became a very meaningful and treasured possession of the church, as well as an aid to worship.
We did the same thing when pastoring at Toronto Alliance Church, with a special dedication on an Easter Sunday. Children carried it in in procession, and a few shared testimonies of their experience working on it.
The symbolic meaning of taking junk and/or broken pieces that normally are discarded/rejected, and then making something beautiful out of them, is to me a picture of the grace of God in all of our lives. I like to think of cherishing the brokenness as gifts from God with which we are entrusted to make something of beauty.