A Silver Necklace is a common Amulet that's primary purpose is to sell for gold.
Sapphire necklaces are popular among Baldur's Gate's patriars as mourning garb - the heavy teardrop-shaped stones represent the weight of their loss.
Properties
Amulets 
Rarity: Common
Weight: 0.05 kg / 0.1 lb
Price: 25 gp
Where to find
Random loot from chests and NPCs.