Please help identify

[Scotto65]

My brother found this in Glenwood Springs, Colorado he says it's silver ore I'm not sure.

 

Amazon Forum Fav 👍

Family Maps of Hinds County, Mississippi, Deluxe Edition - Grab it through Amazon!

[P.ALLEN]

Crack it open and post another photo, why? The cortex or outside skin looks worn, it betrays the actual mineral/rock type, breaking it open or chipping a fragment off gives you a view of the raw inside.

 

[Scotto65]

 

[Eu_citzen]

Well, do a hardness and streaktest. Or have an assay done, to be really really sure. If I'd expect silver, for what ever reason, I'd be inclined to do so.

 

[DDancer]

How did you brother come to believe its silver ore? Did he collect it from a known mine?
Difficult to say what it is, and ore yes, but having collected material like that in Colorado as a kid I'm inclined to think its more likely to be pyrites, galena or a combination there of as they have similar appearance and are much more abundant in that locality.

 

[IAMZIM]

The black could be manganese, and a lot of other minerals. If you want to be sure an assay like Eu Citizen suggests would be definitive.