The Marie Mancini Pearl and Diamond Ear Pendants . Pair of antique pearl and diamond ear pendants © Christie's 

The Marie Mancini Pearl and Diamond Ear Pendants with larger pearls weighing almost 200 grains each, was sold almost 30 years ago.  The pendants incorporating high quality, white, perfectly drop-shaped, saltwater pearls, weighing approximately 200 grains each,  and with a well-documented, over 400-year-old historic provenance, dating back to the 16th-century, sold at a Christie's auction in New York, in 1979, only for US$ 253,000. 

Portrait of Marie Mancini.

(source: http://www.internetstones.com)