Silver cob 3: with 8

[Tuberale]

I think this is silver based on the thickness and sound it makes when dropped, compared to a silver dime. Looks black and tarnished. Trying to determine what it is before trying harsher cleaning regimens on it.

Photo silver4 seems to show a central shield, possibly with an animal inside, and a thick line above. On the left-hand bottom appears to read 171.

Photo silver4a shows another 8 in the upper-right quadrant, but nothing else that I can easily make out.

Coin appears to be a silver cob, just slightly larger than a nickel.

[Mackaydon]

8 maravedis cob

[Tuberale]

Thanks Don!