Ruling on buying diamonds on the Internet
Question

                I hope that you can tell me the ruling on buying diamonds on the Internet.

I know that it is not permissible to buy or sell gold or silver on the Internet.

But with regard to diamonds, I have not seen any fatwa that permits or forbids that. Please note that I want to buy them to wear them, not to deal in them.
Praise be to Allah.
    In the answer to question no.
    34325 it says that it is not 
    permissible to sell gold or silver on the Internet. That is because this 
    transaction delays taking possession of the price for the product, which is 
    not permissible when selling gold and silver. 

    As for selling diamonds, it is permissible to pay the price 
    in advance or to delay it. 

    Based on that, there is nothing wrong with buying or selling 
    them on the Internet. 

    But there is another problem, which is that it is difficult 
    to grade diamonds precisely, so they should not be bought except after 
    seeing them, because the grades vary a great deal and the price and the 
    purchaser’s interest in buying may vary accordingly. 

    Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said: 

    With regard to things of which the quality cannot be known 
    through (general) description only, such as gemstones and pearls and the 
    like, it is not permissible to sell them on the basis of (general) 
    description, because they may vary greatly. One pearl may be worth, for 
    example, a thousand riyals and another may be worth ten riyals, so it is 
    difficult to know the exact quality. So it is essential to grade them 
    precisely so that there will be a clear understanding of the item and there 
    will be no dispute when it is delivered. 

    End quote from ash-Sharh al-Mumti‘, 8/150 

    Based on that, if it is possible to convey a precise idea of 
    the quality of an item through a description in terms known to people of 
    expertise or if a photograph can be taken and presented in such a way as to 
    convey this precise idea, then there is nothing wrong with selling it on the 
    internet. But if the description is not sufficient and the picture is not 
    sufficient either, then it is not permissible to sell it (on the Internet), 
    because that will lead to disputes between the seller and purchaser in most 
    cases. 

    And Allah knows best.