White cultured pearl pendant necklace with white Sapphire in 14k gold

White Cultured Freshwater Pearl Cluster pendant with white sapphire. set in sterling silver with 14k gold overlay , see 925 stamp. chain 18" Beautifully size and colour matched cultured pearls. Accented with glittering white sapphires. Why is there such a difference between pearl earrings that may look similar? Generally it is the quality of the pearl , all other things being equal. price firm, thank you, unless bundled in 3+ items.