
Кто угадает, что это за красный камень среди сапфиров и бриллиантов?
Carnelian, diamond and sapphire pendant by Cartier - Yellow gold and platinum. Signed "Mtd Cartier". Ca. 1930. Highly decorative, exceptional brooch or pendant with central, large flat cabochon-cut carnelian sun (with closed true-foiled back), approx 3.8 cm x 2 cm, with a surround of Fine cornflower blue oval and drop shaped facetted sapphires, altogether approx 6:10 CT, and old-cut diamonds, altogether approx 4:10 CT.
https://www.pinterest.com/pin/259871840975684231/
Это обычный сердолик!
Ну, не совсем обычный - очень красивый.
Сердоли́к, или карнео́л — минерал, красновато-розовая, жёлто-красная или оранжево-красная разновидность халцедона. Название минерала связано с окраской камня (от лат. cornus — ягода кизила), а сердолик — от греческого названия этого камня (др.-греч. σαρδόνυξ)...
https://ru.wikipedia.org/wiki/Сердолик
Еще немножко сердоликовых драгоценностей:

Гемма из карнеола в золотой оправе
http://englishvkartinkakh.narod.ru/index/0-2
Cypriot Carnelian Earrings
http://store.metmuseum.org/earrings/cypriot-carnelian-earrings/invt/09023110


antique tuareg silver and carnelian rings
https://www.pinterest.com/pin/556264991446259432/
https://www.pinterest.com/pin/154670568429160344/


Carnelian and Gold Bracelet. Nubian, Meroitic Period, 1st century B.C. Nubia, Sudan. Braided gold wire bracelet. Between the two strands, a gold rosette in the center with a gold lotus flower on each side and gold ornaments alternating with carnelian beads. On each end a lotus flower terminating in a loop fastener.
https://www.pinterest.com/pin/354095589426542847/
Roman Gold Ring, comprising of a band crafted with twisted gold strands representing a torque supporting a deep circular bezel decorated with fine filigree, set with a beautifully carved carnelian intaglio, dating to the 2nd/3rd Century AD
https://www.pinterest.com/pin/39054721745509474/


Ancient Egyptian gold ring with carnelian gemstone carved into a cat
Third Intermediate Period, 1070 - 1712 BCE. (The British Museum)
https://www.pinterest.com/pin/504262489502225600/
A GREEK GOLD AND CARNELIAN RING HELLENISTIC PERIOD, CIRCA 4TH-3RD CENTURY B.C.
https://www.pinterest.com/pin/235735361722917070/