🔎 UNIDENTIFIED is it a quartz?

[amizengo]

Hello.
We found this stone it weighs 250gms dimensions 6cm by 7cm by 9 cm.When exposed to sun rays it gives rainbow colors. What is this?

 

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[Red-Coat]

From the high clarity, angular shape and conchoidal fracturing, I would assume it's a piece of modern man-made glass.

 

[gillious]

Look through one of the angled sides. You may be surprised. It looks very close to a prism I made a ton of for a former employer. I don't recall what they went into but it was similar affect as looking at one mirror of a periscope.

 

[Kray Gelder]

I agree, broken optical glass piece from unknown instrument.

 

[bartholomewroberts]

Binocular porro prism would be my guess.. Rough condition however

Micheal

 

[Back-of-the-boat]

I also think it is from binoculars I opened up a pair to clean them up and the prism glass piece inside has the same shape.

 

[amizengo]

Thanks for the replies.
We will take the stone to a lab to find out more if its man made or volcanic glass.

 

[Red-Coat]

Thanks for the replies.
We will take the stone to a lab to find out more if its man made or volcanic glass.

By all means do that, but it's certainly not volcanic glass. I think you have your answer, that it's man-made optical glass and likely a broken prism.

 

[gillious]

Thanks for the replies.
We will take the stone to a lab to find out more if its man made or volcanic glass.

I am a fan of lab testing myself but I can say for 100% certainty it is not volcanic glass. I have been machining glass for over 20 years. Glass does not fracture in perfect angles and does not form that clear on its own. The frosted coating on the outside also is a clue that its man made glass. The only real question that remains is what the prism came from. Binoculars seems to be the most probable answer given all reasonable uses for a prism that size. But good luck on the lab test.

 

[creskol]

maybe not a quartz, but it could be 1/2 gallon

 

[Riverbum]

Binocular prism......... see the frosted look on the sides of this prism. Looks like its been handled a little rough

 

[Doubter in MD]

maybe not a quartz, but it could be 1/2 gallon

Speaking of quartz...
Q. What do an elephant and a Timex watch have in common?
A. They both come in quartz.