<p>It can be hard to distinguish man-made smoky quartz from natural smoky quartz. Traditional methods for irradiation to convert quartz to smoky quartz tends to leave the quartz crystals looking more black than translucent smoky brown.  This is caused in part by the rapid irradiation time for man-made smoky quartz.  I am sure a more patient man-made process could produce more naturally smoky quartz.</p>
<p>The best way to determine if smoky quartz is man-made or not is to know the location for the quartz specimen.  Arkansas, USA produces mostly clear quartz and very little natural smoky quartz.  Dark smoky quartz from Arkansas is almost certainly artificially made.  I have a specimen of dark smoky quartz which is almost black from Bear Lodge mountain, Wyoming that is definitely natural.</p>
<p>Best practice, if a smoky quartz specimen does not have a well known location, assume its man-made – never pay a lot for it.</p>

CC BY-SA 4.0
2019-01-25T19:25:10.753Z
2022-10-29T22:04:11.790Z
2022-10-29T22:04:11.790Z
Earth Science Expatriate
<p>I want to purchase a piece of smoky quartz crystal, but am not sure if it is irradiated.  Is there a way to tell if it has been irradiated?  Thank you.</p>

CC BY-SA 4.0
2019-01-20T07:59:26.693Z
From the little information I found, it appears the gray color of all smokey quartz is produced by [gamma radiation](http://yourcrystaljourney.com/irradiated-crystals-what-you-should-know/). Artificially grayed smokey quartz has been irradiated with cobalt 60 gamma rays. Naturally grayed smokey quartz has been irradiated by gamma rays from natural geological sources such as potassium-40 and members of the uranium and thorium decay series. For quartz to turn gray it must contain traces of aluminum.
Fred
CC BY-SA 4.0
2019-01-28T16:32:28.103Z
As an innocent bystander ;-) who knows nothing about this I would like to see in your question why this is relevant....
Jan Doggen
<geology>
How do you tell if smoky quartz has been irradiated?
Cindy
# How do you tell if smoky quartz has been irradiated?

(Asked by: username_0 on 2019-01-20)

I want to purchase a piece of smoky quartz crystal, but am not sure if it is irradiated. Is there a way to tell if it has been irradiated? Thank you.

**Tags:** geology

> **Comments:**
> **username_1**: From the little information I found, it appears the gray color of all smokey quartz is produced by [gamma radiation](http://yourcrystaljourney.com/irradiated-crystals-what-you-should-know/). Artificially grayed smokey quartz has been irradiated with cobalt 60 gamma rays. Naturally grayed smokey quartz has been irradiated by gamma rays from natural geological sources such as potassium-40 and members of the uranium and thorium decay series. For quartz to turn gray it must contain traces of aluminum.  
> **username_2**: As an innocent bystander ;-) who knows nothing about this I would like to see in your question why this is relevant....  

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## 1 answers

### Answer by username_3 on 2019-01-25. Score: 3

It can be hard to distinguish man-made smoky quartz from natural smoky quartz. Traditional methods for irradiation to convert quartz to smoky quartz tends to leave the quartz crystals looking more black than translucent smoky brown. This is caused in part by the rapid irradiation time for man-made smoky quartz. I am sure a more patient man-made process could produce more naturally smoky quartz.

The best way to determine if smoky quartz is man-made or not is to know the location for the quartz specimen. Arkansas, USA produces mostly clear quartz and very little natural smoky quartz. Dark smoky quartz from Arkansas is almost certainly artificially made. I have a specimen of dark smoky quartz which is almost black from Bear Lodge mountain, Wyoming that is definitely natural.

Best practice, if a smoky quartz specimen does not have a well known location, assume its man-made – never pay a lot for it.


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