Is my coin real?

This coin is 16.32mm wide and .68mm thick. It's 1.54g And is more than 14k my  Mizer 24 says 16k but acid test says more like at least 18k. Is it real?

It's really real but very worn. 

It is a 1/2 Escudo from king João V minted in Lisbon.
By law 04APR1722 its weight is 1.8 g with gold 916.6 (22K).

ALL gold coins from Portugal are Au 916.(6).

½ Escudo - João V (Lisboa, Bahia, Rio and Minas mints) - Portugal – Numista

Thank you,I appreciate your information and help. The coin is so thin I wasn't too sure. But all you wrote makes sense .