Wearing precious stones
Question

As you know, many of our "Islamic" cultures have been overwhelmed by superstitious practices from other cultures that people hardly realize they are at fault, assuming their culture to be pure and doubting what Islam says. I have recently heard that wearing certain stones brings certain types of omens, both good and bad. Specifically, someone mentioned that I should not purchase diamond jewelry for my wife since certain bad signs are associated with it.  Is there anything Islamic related to this at all?.
Praise be to Allah.Undoubtedly this is a kind of myth which has no basis in the sharee’ah of Allah. 
Allah says concerning women (interpretation of the meaning): 
“a creature who is brought up in adornments (wearing silk and gold ornaments, i.e. women), and who in dispute cannot make herself clear” [al-Zukhruf 43:18]
The adornments in which the female is brought up include gold, silver and precious stones. 
Allah has blessed mankind and the jinn with the things that come out of the sea and rivers such as pearls and coral. Allah says (interpretation of the meaning): 
“He has let loose the two seas (the salt and fresh water) meeting together.
Between them is a barrier which none of them can transgress.
Then which of the Blessings of your Lord will you both (jinn and men) deny?
Out of them both come out pearl and coral.” [al-Rahmaan 55:19-22]
 Diamonds and other kinds of precious stones are among the adornments which women are permitted to wear, but this adornment should not be shown to “strangers” (i.e., non-mahrams).
 Wearing these stones is not an omen of anything, either good or bad. This is one of the false beliefs which the believer should be above believing.
 But the Muslim woman should beware of pride or arrogance that may affect her when she wears these things.
 And Allah knows best.