Fig. 1. Photos of freshwater cultured white pearls samples from Anhui
(a): The first batch of samples; (b): The second batch of samples; (c): The third batch of samples

Fig. 2. The Raman spectral of peals
(a): Raman spectra of three different batches of white pearls; (b): Magnified peak of 1 132 cm^-1; (c): Magnified peak of aragonite

Fig. 3. The whiteness values of the three batches of samples

Fig. 4. Photomicrographs of freshwater cultured white pearls from Anhui (x10)
(a): 3.6; (b): 1.3; (c): 2.5; (d): 2.2