Originally Posted by fm747

As a chemist I can provide a scientific explanation for this:
The idea that caviar gets a bad taste when eaten or served with ANY metal untensil is an urban myth. However, caviar contains a high concentration of proteins with a very high sulfur content. If one eats (or serves) caviar with SILVER utensils (as where commonly used in the 18th and 19th century) then the sulfur containing proteins in the caviar "react" with the silver and oxidise it, resulting in the silver turning darker in colour "tarnishing" and the caviar gets a different taste. Since back in the 18th and 19th century plastic was not yet known and not widely used, an alternative non-silver material had to be found to serve caviar and that happened to be mother of pearl.
This tarnishing of silver by caviar also happens with silver plated utensils but NOT with stainless steel utensils that are used in restaurants or airlines.

If my memory is not mistaken TG and LH do use mother of pearl spoons to serve their caviar.