Pearl Quality Winding(maki) and Luster(teri)

A pearl oyster is the layer in which the mother pearl oyster, the pearl oyster, secretes a nacre around its nucleus.
The nacre layers overlap like a stack of bricks. Thousands of these nacre layers are properly stacked to create a iridescent glow of pearls.
Teri and winding thickness are not proportional. There are pearls that have strong terry even in thin rolls and weak terry even in thick rolls. It is as if the nacre is neatly folded.

Luster (teri) is the brilliance of pearls.
The brilliance of pearls is said to be the interference of transmission. Light shines into the pearl and returns like a V, which is reflected in our vision. That is, light enters the pearl, absorbs the color inside the pearl, and is reflected in our vision. When the light shines on the mirror, it's just dazzling and you can't see the color. This is a reflection of light.
If the nacre is not folded neatly, it will not come back like a V. It is this phenomenon that makes brightly colored pearls look different in color.