That is old. These Ptolemaic gold oktadrachms are impressively large,
and this particular specimen is impressively preserved too.
Here's a gold coin, not as large, that's about 125 years older:
http://rg.ancients.info/alexander/Stater_lifetime.jpg
Alexander the Great gold stater, 8.61g, 17.5 x 17.5 x 3.5mm, 100 percent
gold (with a margin of error 1.02) but having no detectable traces of
silver, copper, lead, nickel, or iron according to an EDS analysis I had
done, minted c. 328-323 BC, during Alexander's lifetime, in Abydos,
Troas, Asia Minor, the closest Greek city from Europe on the Asiatic
bank of the Hellespont and the location where Alexander crossed into
Asia in 334 BC at the outset of his conquest
As long as I'm having fun showing off, here's one that's older still, an
additional 400 years older:
http://www.forumancientcoins.com/reidgold/misc/Lydian_trite_15.jpg
Lydian Lion trite (or stater), 4.71g, 13 x 10 x 4 mm, made of electrum,
a gold and silver alloy, in this case about 55 percent gold according to
metallurgical analyses of similar coins done by others, arguably the
world's first coin, c. 600 BC, minted by King Alyattes in the then
independent empire of Lydia, now part of Turkey, about a half century
before it was conquered and absorbed into the Persian empire, later in
turn conquered by Alexander, with the area subsequently ruled by the
Seleukids, Romans, Byzantines, and Turks
--
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