In order to determine the difference between a real and fake Tiffany necklace, you must know what to look for, especially the smaller details. If the craftsmanship looks in any way shoddy or lacking, it is likely not a Tiffany necklace. Knowing in advance how to determine a real Tiffany necklace will save you money. In addition, if you purchase a fake Tiffany necklace and attempt to return it, a Tiffany vendor will not accept it.
Consider the vendor. Most authentic Tiffany items will come from Tiffany's itself, and not from any wholesale or outlet store. Beware of independent vendors claiming they have many "new" Tiffany items on sale, as they are likely knock-off brands.
Test the weight. Tiffany necklaces and tag bracelets will feel heavy, because they are made of .925 sterling silver. A Tiffany necklace will appear dark silver or even slightly gold in photographs; sellers of fake Tiffany products may try to paint the piece to give it a bright white or silvery appearance.
Examine the links. The links of a real Tiffany's necklace will be soldered together, rather than pinched. It may be difficult to tell where the links are on the necklace. The lobster clasp will also appear to be carefully crafted and detailed. The number "925" will be stamped at the base of the clasp. Heart lifesaver necklaces, however, will have this stamp at the top of the bail.
Check the length and engravings. The Tiffany toggle necklace is 16 inches in length, while the dog tag and heart tag necklaces are 15.5 inches in length. Note the "Please return to Tiffany" engravings. The pendant of the toggle necklace should not have any engravings, but will have a "Tiffany & Co." engraving on the lifesaver part of the necklace. With the double heart necklaces, the bottom pendant is engraved with "Tiffany & Co."