Thanks Arthur. You are correct, of course. I should have read the information in the link you initially provided. That answers my query.
--Previous Message-- : I am not enough a specialist in gems and their : natural properties to be able to answer your : question. : : When I mentioned the necklace's sparkle, I : was thinking of the diamonds rather than of : the rubies. : : And yes, the red stones are definitely : rubies, as mentioned by Christie's for the : auction in 2005 (and I am sure that : Christie's has jewel specialists who are : able to distinguish a ruby from a spinel ): : : http://www.christies.com/lotfinder/lot/an-antique-ruby-diamond-and-pearl-necklace-4577969-details.aspx?from=salesummary&intObjectID=4577969&sid=b39a5c23-ae17-4197-8a3d-77b7e1a42607 : : : --Previous Message-- : Arthur, is it that the stones in the ruby : necklace show as pink in the photographs : because they are a blue based red? Or is it : because of the lighting in the display : cabinet and the venue? Because you mentioned : the sparkle of this necklace, I also : wondered if these stones might be spinels : and not rubies. Some spinels show wonderful : colours in the blue-red to pink range and : good spinels have a degree of sparkle not : seen in rubies. However, I have no doubt if : a reputable jeweller is selling an item as a : ruby necklace, the stones will be rubies, as : the differences are obvious to a gemologist : examining stones. Did you see anything : indicated by the jeweller that these stones : are rubies? If they are rubies, the colour : might indicate where they came from. : : : :