Discerning
/dɪˈsɜːrnɪŋ/ adjective mediumAble to judge or perceive things clearly and accurately, especially subtle differences.
A discerning shopper, she could tell the handmade rug from the machine-made copy at a glance.
Memory Trick
Discerning contains 'discern,' meaning to separate or tell apart — a discerning eye separates the genuine from the fake.