Please help me identify this very unusual (to me) rock

[BobbyGman]

I'm a newbie rockhound having recently moved to Miami Arizona. I found this rock in Globe AZ. It's very hard. The porous side a file will hardly touch. It's approx. 6" x 4" x 4". Any help as to it's nature and value is very much appreciated. thanks

 

[bluveinthrobber]

Hmm some type of quartz geode id think but dont take my word as im very inexperienced still

 

[BobbyGman]

Thanks . A friend suggested it may be a fire agate. I only know that it's nothing like I have seen before.

 

[Eu_citzen]

Most seem to be chalcedony. The glassy one is interesting; see if a quartz will scratch it. Could be opal, which will be scratched by quartz.

 

[BobbyGman]

Thanks I'll try that. All the pics are of the same rock. The pitted side is very hard. The whitish filling ( so to speak) is softer. It seems to have 3 textures.

 

[IAMZIM]

When I saw the first pic I thought you had found a giant arrow head lol! Looks very much like "agate" type material to me, so chalcedony is my guess as well. Cool rock!

 

[stdenis_jd]

Call me crazy, but if you can find out what that white material is and find a way to remove it if possible, you might have some crystal points under that white mess...I'd be curious to see if they look like citrine points...anyone else think that might be just calcium deposit coating crystal points? I can't imagine it would be calcite. If the hard stuff is in fact silicate/chalcedony, you should be able to safely soak the whole thing in iron-out or something of the like to loosen up or remove the white stuff. I would make sure to ID the white first somehow

 

[BobbyGman]

Thanks

 

[BobbyGman]

I see what your thinking. The white tho is also crystalline. I think I can get a scraping and have it analyzed. I appreciate all of your input.

 

[smokeythecat]

It is basically a variety of gem quartz. Quartz is SiO2, silicon dioxide, one of the most common elements on earth. NOW>>>>>you have a gorgeous piece of agate and/or chalcedony. Both are the same essentially - silicon dioxide. The type you have people make into jewelry, cabochons. You have a might nice find there. I wouldn't touch it, just display as is.

 

[BobbyGman]

Thank you for your input. I agree, I will be careful to maintain the rock's integrity. It's value to me right now is in its uniqueness. I intend to try and discover how unique it is. I'm hoping the process will teach me more about earth science.