This is the By The Yard Necklace by Tiffany & Co. SA rank: This is a beautiful polished item.
Brand name: Tiffany & Co.
Model name: By The Yard Necklace
Size
Chain length: 40.5 cm (15.9 in) (flat including top) Pendant:
Height: 4.2 mm (0.17 in) x Width: 4.3 mm (0.17 in): 2 g
Accessories: None
Material: 750 Gold

Condition Guide:
S: Like new by the store's standards
SA: Almost unused, overall pristine
A: Excellent condition
AB: Great condition, minor signs of use
B: Good condition, signs of wear from normal use
C: Noticeable scratches, dirt, or signs of use
D: Heavily damaged or in need of repair
Item with difficulty being called C: