Help! Black grit in my Art Clay Silver.

[dancealicat]

I am pretty new to Art Clay Silver. The new pack that I just opened up was a little dry, so I added a couple drops of water and kneed it up really good. Then I wrapped it up in plastic wrap, put it back in the bag, and then that bag in a zip lock. The next day I took it out to make a project....there was black grit all over it! Is it mold? It felt like dirt. What is it and how can I avoid it in the future?? Thanks!

[Polly]

That sounds too quick for mold, although that would have been my first thought too!

Seems like there might be something odd in your tap water, and the silver reacted with it.  Kurt (MetalMan) should be chiming in soon with his ideas.  In the meantime, what part of country/world are you in, and are you on city water or well water? Is there anything unusual that you're aware of in your water supply? What did you knead the ACS up with (hands ... tools that might have iron in them?), or on (what was the surface ... wood, plastic, kitchen counter...)?

[Metalman]

Dancealicat - all of Polly's questions below are the way to think about this.ultimately - try to answer/think about them and let us know.
One solution for the water aspect is to use distilled water.  I have had a black mold on clay I left wrapped up for a long period of time  [is it really warm where you are working?] The mold seems to knead back into the clay and doesn't affect firing - I usually don't worry about it.  You said it felt like dirt - can you isolate any particles? is there actually a hard, foreign bit in the clay?
Keep us posted.  Hoping this helps
Metal Man

That sounds too quick for mold, although that would have been my first thought too!

Seems like there might be something odd in your tap water, and the silver reacted with it.  Kurt (MetalMan) should be chiming in soon with his ideas.  In the meantime, what part of country/world are you in, and are you on city water or well water? Is there anything unusual that you're aware of in your water supply? What did you knead the ACS up with (hands ... tools that might have iron in them?), or on (what was the surface ... wood, plastic, kitchen counter...)?