your heirloom pearls sounds beautiful. Being in their original box will add to their value, and also indicates they are in good condition. Dust contains minute particles of quartz and over time these minute particles will damage the surface of pearls. The length, and the diameter of the pearls will also be part of the valuation equation.
The Earlier versions of Cultured pearls are my favorites. The introduction of Cultured pearls, courtesy of Mikimoto injected an exciting new dimension to jewelry and pearls. Before cultured pearls opened the ball, Natural Pearls were worn mainly among the upper circles.
One really should examine the pearls and this is why I would not recommend having your pearls appraised and valued on-line. Kathy, if you would like a valuation of your pearls, for more details, Contact Here.