But it's fine silver.

As I mentioned in an earlier post, working on crosses in metal clay is delicate work.  I can't tell you how many pieces I have broken during the sanding process.  It's not so much sanding the edges but trying to sand the surface that I seem to have the most trouble.

This past week I was making a cross for a friend when I broke it three separate times.  Repairing metal clay in the dry state is fairly easy (as long as the edges line up.)  And, it's usually just as sturdy as if it hadn't broken.  The repairs went well...... until I dropped it.  It broke in two "different" places.  Once again, back to repairing it.  This time though I pasted it to a bigger cross to give it strength (and made my friend a new one.)

After firing the piece I added a patina.  Darn..... wouldn't you know it the patina came out a beautiful shade of blue. I decided to leave it (although it will continue to darken.)  The reason I say darn, is because fine silver is expensive and now it doesn't look like silver.  It looks like copper.  

Oh well, I like it and hopefully someone else will too. 

It's a mystery!

Today I fired five more pieces of fine silver, thinking I could make a few more pieces for the Oil Heritage Craft Sale this weekend.  The pieces were fired as usual, 1470 degrees for forty five minutes.  They came out of the kiln looking white  (as usual.)  I brushed the silver to let the shine show through (as usual.)  

Then I threw them in the magnetic tumbler (as usual.)    This is where "the usual" ends.  The first two pieces were in the tumbler about ten minutes before I tossed in the other three pieces.  Five minutes later I took out the first two pieces....... all shiny and silver.  Twenty minutes later I took out the other three pieces and saw something I've never seen before.  And, for which I have no explanation.  

The top left piece came out looking like a piece of copper.  The top right piece is a combination of dark copper, magenta and  blue.  The left bottom piece is a light gold color and the right bottom piece is the typical silver color (as was the other piece that went in first.)  

Most of the pieces are the colors I would expect after dipping them in Liver of Sulfur (not after taking them out of the tumbler.)  Somehow my shot has been contaminated but it is so strange that two of the five pieces in the same tumble batch are okay.  

So now I have to clean my tumbler with flat coca-cola and try it again.  I plan on re-firing the pieces to remove the coloring as they did not polish up well at all.  (Obviously they won't be ready for this weekend's sale.)  

This is a mystery to me and one I hope to solve.