Highly Unusual 18K Yellow Gold, Sapphire and Ancient Greek Tetrobol Coin, 400 B.C. Ring in Open Pattern. Open ring in 18K yellow gold and sapphire ring which enhance a Greek tetrobol coin from the Macedon, Chalkidian League, ca. 400 B.C. Obverse is the head of Apollo, facing left wearing laurel wreath on his head. On the reverse is the image of a kithara with five strings. The coin is in exceptional condition given the high relief which is quite a luxury given most coin rings rarely have such a quality coin specimen. Apollo indeed appears to be staring at the sapphire "egg" perhaps contemplating which came first. Size 6.25 and weighs 8.35 grams. A terrific ring sure to be noticed. Estimated Value $600 - UP