Well centered Ancient Greek Silver Drachm of Apollonia Pontika in Thrace, 450 - 400 BC.
Obverse: Anchor with A to left and crayfish to right.
Reverse: Gorgoneion with tongue protruding.
A standard currency in Thrace in the 4th century BC. but a high rarity factor in the modern age. Content silver,  2.8 grams, 13 mm diameter