Okay I have previously reviewed this necklace and gave it 5 stars.  Unfortunately it now has tarnish so badly that it is no longer wearable.  I have had it for only a few months.  I went to the sellers website and did exactly what they said to clean the necklace.  Lined a bowel with aluminum foil laid necklace down covered with1/2 t. salt 1 tablespoon baking soda covered with boiling water. Did this 3 times letting it soak for at least 5 minutes.  Still black in places.  I am going to order it again.  I am calling the seller to see what happens.  BTW I used this method to clean a silver chain the is at least 15 years old.  It looks like new.  Hum.  One must be sterling silver.  I wonder what this one is??
BTW:  Just call me a sucker because I am ordering it again and hoping for better results.  I love the chain it's beautiful but at this point it is also disposable.