Tiffany & Co 925 Silver Dangling Large Solid Heart Pendant Necklace

I purchased this myself from Tiffany's so I'm sure of its authenticity. However I purchased it over 10 years ago and do not have the receipt. Just pulled it out of my drawer and it was quite tarnished (after many years of not wearing it) so I cleaned it with a silver cleaner. Could probably use a professional clean. There is a small knot that I'm not patient enough to get out but doesn't seem that difficult. Feel free to ask questions! update: got the knot out :)