According to the different growing waters, pearls can be divided into seawater culture and fresh water culture. According to different growth modes, pearls can be divided into natural seawater pearls and natural freshwater pearls. According to the presence or absence of pearl core, pearls can be divided into seedless culture and nucleated culture, free culture and shell culture.
Pearl may have halo, which can be divided into strong halo, obvious halo and general halo. According to the quality factors, decorative pearls can be divided into two grades: jewelry-grade pearls and handicraft-grade pearls, that is, handicraft-grade pearls can not meet the requirements of jewelry-grade pearls. In addition, the pearl shapes can be divided into A 1, A2, A3, b, c and h; Gloss grades are divided into A, B, C and D, and Pearl is a member of colored gems.
grade scale
Due to historical tradition and moderate price, pearls occupy an important position in today's jewelry industry, especially jewelry e-commerce. However, the development of pearls still needs to solve an important obstacle, that is, how to quantitatively and systematically identify the authenticity and quality of pearls, which involves the formulation and implementation of pearl grading standards.
The classification standard of pearls is divided into two parts: the classification of seawater pearls (including Nanhai pearls, Tahiti pearls, Japanese seawater pearls, etc.). ) and the classification of freshwater pearls. The classification of freshwater pearls includes the following five aspects: color, size, shape luster, smoothness and collocation (only for multiple pearl ornaments). In addition to the above five aspects, the classification system of seawater pearls also includes the thickness of pearl layer.