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Helenite?
https://gemologyonline.com/Forum/phpBB2/viewtopic.php?f=86&t=22247
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Author:  Dan&Sally [ Mon Jan 18, 2016 1:22 am ]
Post subject:  Helenite?

Some kind of bright green stone from Mt St Helen? or synthetic something with a catchy name. If its natural, say a feldspar crystal.. what would be the most likely ingredient for its green color? Iron, chromium, manganese, or some combination? Or would that depend on if it was idiochromatic? is that right? The one thats part of its basic chemical make up and not the one swapping electrons. . . . Im new at this can you tell :smt065

Author:  Dan&Sally [ Mon Jan 18, 2016 9:26 am ]
Post subject:  Re: Helenite?

Ok it's a synthetic something, even glass maybe. So now we are talking about sharing electrons to get color or can it still be from its basic chemical structure. ?

Author:  Stephen Challener [ Mon Jan 18, 2016 12:11 pm ]
Post subject:  Re: Helenite?

It's glass with (allegedly) a pinch of mt st helens ash mixed in. It comes in a variety of colors from what I've seen.

Author:  Dan&Sally [ Mon Jan 18, 2016 4:08 pm ]
Post subject:  Re: Helenite?

Then the color is from adding minerals that share the electrons. Charged something , #¥*< have to look it up. Getting old sucks, the memory just doesn't retain things the way it used to.

Author:  Dan&Sally [ Mon Jan 18, 2016 4:18 pm ]
Post subject:  Re: Helenite?

Charged transfer was what I was after.

Author:  Stephen Challener [ Mon Jan 18, 2016 5:13 pm ]
Post subject:  Re: Helenite?

There are quite a few ways to color glass. I'm not sure what they would use in helenite, but no doubt it's the same as any old glass.

Author:  Barbra Voltaire, FGG [ Mon Jan 18, 2016 6:33 pm ]
Post subject:  Re: Helenite?

Helenite
A novelty colored stone made from the ash of the 1980 Mount St. Helens eruption
Image


What causes the colors in glass?
The Glass Packaging Institute wrote:
Color can be obtained by simply adding small quantities of different oxides:

Chromium (for green)
Cobalt (for blue)
Nickel (for violet/brown)
Selenium metal (for red)

The raw materials used in commercial glass making contain iron oxide as an impurity, which imparts a yellow/green color to the glass

To offset the yellow/green when making flint (or “colorless”) glass, other colors are introduced by adding selenium (for red) and cobalt (for blue) in proper proportions to yield a gray glass that appears colorless, hence the term “decolorization.”

Green Glass

Green Glass is made by adding non-toxic Chrome Oxide (Cr+3); the higher the concentration, the darker the color.
Green glass can be either oxidized, such as Emerald Green or Georgia green, or reduced, as with Dead Leaf green.
Reduced green glass offers slight ultraviolet protection.

Read More

Author:  Dan&Sally [ Tue Jan 19, 2016 12:13 am ]
Post subject:  Re: Helenite?

Ok but glass color is still the process of charged tranfer. Share the electrons which then absorb some light and reflect the rest back which we see as a color.
In electronics it would be similar to the super hetrodine process of mixing frequencies and then selecting the exact ones with a bandpass filter. Funny but they use crystals to generate the frequencies in electronics by exciting them with voltage which makes them vibrate at a specific rate depending on the thickness of the crystal. Thick is low freq and slow wavelength, thin is high freq and fast wavelength.

Author:  Barbra Voltaire, FGG [ Tue Jan 19, 2016 12:30 am ]
Post subject:  Re: Helenite?

Uhmmm, I think you may have skipped a couple paragraphs in the article you are reading on the causation of color in minerals.
Start here
http://gemologyproject.com/wiki/index.p ... s_of_color

Quote:
In electronics it would be similar to the super hetrodine process of mixing frequencies and then selecting the exact ones with a bandpass filter. Funny but they use crystals to generate the frequencies in electronics by exciting them with voltage which makes them vibrate at a specific rate depending on the thickness of the crystal. Thick is low freq and slow wavelength, thin is high freq and fast wavelength.


What does that even mean? Rhetorical observation, please don't explain.
AND, What does any of this have to do with helenite?

Author:  Dan&Sally [ Wed Jan 20, 2016 3:45 pm ]
Post subject:  Re: Helenite?

I drift off like that some times. Original question was covered very nicely. 1st I understand its glass. 2nd it's colored by adding minerals during the melting process. 3rd I think that means the color is generated by the charged transfer of electrons sharing with neighboring atoms. Which then absorb some frequencies of white light and reflect others as the color we see in the crystal. I think I got it

Author:  Stephen Challener [ Wed Jan 20, 2016 4:20 pm ]
Post subject:  Re: Helenite?

There are other coloring mechanisms. For instance, you can get colloidal metallic copper which causes color by (apparently) a similar mechanism to green oregon sunstone.

Author:  AlBalmer [ Wed Jan 20, 2016 4:50 pm ]
Post subject:  Re: Helenite?

Actually, the superheterodyne and filter analogy is kind of neat (but don't ask me if it's accurate :-)).

To get back to faceting, this was the reason synthetic quartz was developed. I wrote some of the control software for a Motorola quartz-growing operation. Too many years ago.

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