Next Article in Journal
Symbiodinium—Invertebrate Symbioses and the Role of Metabolomics
Next Article in Special Issue
Chemical Structures and Bioactivities of Sulfated Polysaccharides from Marine Algae
Previous Article in Journal
Marine Myxobacteria as a Source of Antibiotics—Comparison of Physiology, Polyketide-Type Genes and Antibiotic Production of Three New Isolates of Enhygromyxa salina
Open AccessArticle

Assessing Pearl Quality Using Reflectance UV-Vis Spectroscopy: Does the Same Donor Produce Consistent Pearl Quality?

1
Pearl Oyster Research Group, School of Marine & Tropical Biology, James Cook University, Townsville, Queensland 4811, Australia
2
School of Pharmacy and Applied Science, La Trobe University, Bendigo, Victoria, Australia
*
Author to whom correspondence should be addressed.
Mar. Drugs 2010, 8(9), 2517-2525; https://doi.org/10.3390/md8092517
Received: 12 August 2010 / Revised: 3 September 2010 / Accepted: 13 September 2010 / Published: 20 September 2010
(This article belongs to the Special Issue Marine Biomaterials)
Two groups of commercial quality (“acceptable”) pearls produced using two donors, and a group of “acceptable” pearls from other donors were analyzed using reflectance UV-Vis spectrophotometry. Three pearls with different colors produced by the same donor showed different absorption spectra. Cream and gold colored pearls showed a wide absorption from 320 to about 460 nm, while there was just slight reflectance around 400 nm by the white pearl with a pink overtone. Cream and gold pearls reached a reflectance peak at 560 to 590 nm, while the white pearl with pink overtone showed slightly wider absorption in this region. Both cream and gold pearls showed an absorption peak after the reflectance peak, at about 700 nm for the cream pearl and 750 nm for the gold pearl. Two other pearls produced by the same donor (white with cream overtone and cream with various overtones) showed similar spectra, which differed in their intensity. One of these pearls had very high lustre and its spectrum showed a much higher percentage reflectance than the second pearl with inferior lustre. This result may indicate that reflectance is a useful quantitative indicator of pearl lustre. The spectra of two white pearls resulting from different donors with the same color nacre (silver) showed a reflectance at 260 nm, followed by absorption at 280 nm and another reflectance peak at 340 nm. After this peak the spectra for these pearls remained flat until a slight absorption peak around 700 nm. Throughout the visible region, all white pearls used in this study showed similar reflectance spectra although there were differences in reflectance intensity. Unlike the spectral results from white pearls, the results from yellow and gold pearls varied according to color saturation of the pearl. The results of this study show that similarities between absorption and reflectance spectra of cultured pearls resulting from the same saibo donor are negligible and could not be detected with UV-Vis spectrophotometry. Nevertheless, this technique could have a role to play in developing less subjective methods of assessing pearl quality and in further studies of the relationships between pearl quality and that of the donor and recipient oysters. View Full-Text
Keywords: pearl; pearl quality; pearl oyster; UV-Vis spectroscopy pearl; pearl quality; pearl oyster; UV-Vis spectroscopy
MDPI and ACS Style

Mamangkey, N.G.F.; Agatonovic, S.; Southgate, P.C. Assessing Pearl Quality Using Reflectance UV-Vis Spectroscopy: Does the Same Donor Produce Consistent Pearl Quality? Mar. Drugs 2010, 8, 2517-2525.

Show more citation formats Show less citations formats

Article Access Map by Country/Region

1
Only visits after 24 November 2015 are recorded.
Back to TopTop