Restoring Tarnished Silver Jewelry: Causes & Restoration

Question

Necklace   Hi,
My husband wore his David Yurman sterling silver cross with black diamonds in our condo's pool. A few hours later the sterling silver box chain and the cross had turned a dark brown/black. I have no clue what kind of chemicals are in this pool. Do you know why the chain and cross would change colors like this and is there anyway to restore the chain and cross back to its original state?
Thank you for your time,
Heather

Answer
You can try using distilled water, baking soda, in an aluminum tray. You might want to heat the water first. This should. Help remove most of the tarnish inexpensively. Or you can spend the $$ and buy tarnex or tarnix not sure hot the spell it  but it works well . However neither will bring the shine back. You might have to use a hand cloth or have a jeweler polish it. Make sure he has lots of experience polishing chains. It is easy to destroy one with a polishing machine. Also make sure you rinse with distilled water after cleaning .
I hope this helps, don't forget not to swim in your jewelry anymore.
Chris.