The Chintamani Stone

Between 1923-1928 this stone, which first manifested on Earth many thousands of years before the Cup of Christ, was taken by the great Russian artist and mystic Nicholas Roerich into the heartland of the Far East in order to reunite it with the mother stone it had been separated from, a massive jewel that resided in Shambhala, the Land of the Immortals.

the Chintamani Stone is, apparently, also green in color, since Roerich is on record as also stating that the Chintamani Stone is similar in appearance to a species of meteorite known as Moldavite, which is dark green in color.

the Chintamani Stone was given to the founders of the League of Nations, whose stated goals were the creation of a one-world civilization free of hate and war.

This was the stone that Nicholas Roerich carried back to Shambhala following the collapse of that international organization.
https://www.bibliotecapleyades.net/sociopolitica/sociopol_shambahla11.htm

According to the more esoteric stories of the Chintamani Stone, this substance was brought to Earth from the Sirius star system as a gift from an alien civilization. It’s interesting that the stone’s origin comes from Sirius, a star which the Dogon tribe in Africa refer to as the Eye of the Universe. The Dogon tribe also said to have been visited by Sirius Star aliens. These beings are said to have kept tabs on the Chintamani, assuring that it stayed in the possession of important world leaders, such as Genghis Khan and King Solomon. It was thought to have been kept, at one point, in the Ark of the Covenant, also under King Solomon’s possession. Some even believe it to be the sacred stone of the Kaaba in Mecca, that is so highly revered in Islam.
https://www.gaia.com/lp/content/chintamani/

Because of its unique properties, the Chintamani Stone is reported to have been in the temporary possession of influential personages at important times in humanity's history – people like Akbar and King Solomon – who were entrusted with special missions necessary to humanity's continued development.
http://www.triuneoflight.org/newsletter/shambhala-chintamani-stone.html

Nicholas Roerich, a Russian explorer, artist and mystic who traversed the regions of Asia during the 1920s and 30s, was said to have come into possession of a “magical crystal from another world”, known as the Chintamani Crystal. The crystal, thought to have had magical properties, is believed to have been Moldavite, and was once a talisman of Tazlavoo, the one-time Emperor of Atlantis.
http://sirius-star.ro/cintamani-stone/