This is a ciborium; a vessel in which, among other things, one reserves the Blessed Sacrament to be placed in the tabernacle after Mass. This one belongs to me and I use it whenever a sacristan happens to put it out for use. It came into my possession during my first assignment at St. Ambrose. It sat black and unused on a bookshelf in my pastor's (the Rev. Bob Hilkert) parlour.
One day I told him he should shine it up and use it. He let me have a go at it and it turned out rather swell. When I brought it back he said, "You take it. I'll never use it." Of course I protest - feebly - and soon relented and have been using it ever since.
At one point it was knocked to the floor by an accidental swing of the arm of a parishioner and at that point it had to be repaired and so I also had it replated. Not too long after that it was dropped again (you would be surprised how often that happens) and now the cross is a little cockeyed. But it is still serviceable.
As you can see there is much ornamentation but little of it symbolic.
It is difficult to see here but just below the cup and above the node is a grape and vine design.
The base is quite nice. There are six figures. They were made separately and then attached. Above the figure shown below is an ornate Greek cross barely visible through the glare. This is the side that faces the priest during the Mass. The figure below it is an angel holding a scroll on which nothing is written. (Interesting.)
Moving around the base of the ciborium to the right there is Saint Matthew, Saint John, the Virgin Mary holding the infant Jesus, Saint Mark, and then Saint Luke pictured below.
There are no markings on the bottom of the base to indicate from where it came, how old it is, or whom it may have belonged. Unfortunately I did not get the information before Fr. Hilkert passed on.