Posted by:
summer
(
)
Date: May 14, 2018 06:39PM
Interesting question. Does "turquoise color" mean actual turquoise or something like an aquamarine, tourmaline, etc.?
Here is one article on how turquoise stones can darken with exposure to water or oil:
https://tskies.com/does-turquoise-change-color/The other turquoise-colored stones appear to be stable to water, i.e. aquamarine, tourmaline, and possibly topaz or opal. They are, however sensitive to heat or fracture.
http://www.studleysjewellers.co.uk/gemstone-guide/You might ask your classmate about her ring size. That might narrow it down.