Rough opal? Agate/chalcedony?

[BridgetownTreasures]

Thanks for helping a beginner out! Everyone has been so kind to me as a work my way through my grandfathers amazing collection. We used to go rock hunting together in eastern Oregon, and it’s been such a treat to learn more about his stuff

I’m attaching photos of a great big piece I have had for a while now. I’m not sure what it is, but it bears resemblance to a lot of the smaller rough opal pieces I have found. Is there any way to know without cutting it open? It’s difficult to tell in the photos, but there are many spots that have that bluish pearlescent hue to them, but it is tough to say. I’m really not an experienced hound yet. :-)

Thanks again! I’m so grateful for the info!

 

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[BridgetownTreasures]

 

[Molewacker]

Since you're in PDX you should really check this out -

https://ricenorthwestmuseum.org/

It's awesome for us rock lovers!

 

[BridgetownTreasures]

I’m seeing some specimens of “Blue Mountain Jasper” which makes sense as it is likely from eastern Oregon or western Idaho - near the blue mountains.

 

[DDancer]

Looks like a mix of jasper, agate and crystalline quartz. Interesting mix.

 

[gunsil]

You need to hardness test it, agate is way harder than opal.

 

[A2coins]

That's a great collection he had I've been following your posts I dont know much about rocks but I'm learning as you post em. Keep em coming. Tommy

 

[BridgetownTreasures]

You need to hardness test it, agate is way harder than opal.

This seems to be 7 or above in hardness. I had a small piece of quartz with a decent point on it that I tested in several places - not a scratch or a mark. In fact I was worried I was dulling the point of the crystal!

Found a free rock/mineral ID event at a local rock & gem museum this weekend. I think I'll take it on over. Sure would like to get a saw into it!!

 

[fuss]

The pale colored area looks like common opal, if you have access to a UV light try to see if it fluoresces green, though some chalcedony does as well.

 

[BridgetownTreasures]

For inquiring minds.....here's a link to a folder with a LOT of photos of grandpa's collection...and there's still more to sort through

https://drive.google.com/open?id=1-DDcUfzVod-FSuR0yVlFbmkSbW0d1rK6

 

[Molewacker]

For inquiring minds.....here's a link to a folder with a LOT of photos of grandpa's collection...and there's still more to sort through

https://drive.google.com/open?id=1-DDcUfzVod-FSuR0yVlFbmkSbW0d1rK6

Oh, I'd love to get a black light on that collection!

 

[BridgetownTreasures]

Molewacker, if anything special catches your eye, let me know! My eye is still being trained! I do have access to a black light...

 

[Ponchosportal]

As a hydrated silicate Opal will be less than 7. Although the greasy appearance and micro-crystalline material certainly has an opal appearance.