Natural silk -- the fibre spun by the silkworm to fabricate its cocoon -- is a triangular fibre, shaped like a prism, which reflects and refracts any light.
The silk fibre is triangular, so it reflects light from all sides.
Its lustrous appearance makes it attractive
The fibres are triangular prism like structure. so the silk cloth refracts the light falling on it at different angles and gives a shimmering appearance.
The cocoon of the silkworm is produced by the animal in a trianglular shape, so that for the length of the strand, light is reflected from most any angle.
taffeta
1)it absorbs sweat.rayon clothes are therefore preferred over other synthetic fibers in summer. 2)it is shiny and lustrous and resembles silk in appearance.
The appearance of iodine crystals: lustrous, metallic, gray.
example
Elemental iodine has a lustrous metallic gray color, and its vapor is violet. Source: Wikipedia.
Protein found in silk,a strong,soft,lustrous fibre made of fibroin, a structural protein consisting almost entirely of stacked antiparellel beta plated sheets.
The elements of the d-block are mostly considered to be metals and have a lustrous metallic appearance.
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Iron is not beautiful but dull is an exaggerated word.