This is Tiffany & Co.'s Open Heart Necklace. SA rank: Polished beautiful item.
Brand name: Tiffany & Co. Model name: Open Heart
Size
Chain length: 41 cm (16.14 in) Pendant:
Height 2 cm (0.79 in) x Width 2.2 cm (0.79 in): 9.3 g
Accessories
None
Material
Pt950

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