# A large crystal well largest



## etack (Feb 14, 2014)

My wife works for Miami University and she thought that I would like this story.

would be neat to hold one.

http://miamioh.edu/news/top-stories/2014/02/rakovan-gold-research.html

Eric


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## niteliteone (Feb 14, 2014)

Sure wish I had a couple of those crystals 8) 
Thanks.


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## g_axelsson (Feb 14, 2014)

Now I know what to do with my gold! :mrgreen: 

Thanks for sharing.

Göran


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## Lou (Feb 14, 2014)

These can be grown from the gas phase-- here is one that my friend Ivan made:

http://www.periodictable.ru/079Au/slides/Au8a.jpg


They can grow as large as your patience and, if good feedstock is used, can be amongst the purest gold in the world (6N+).


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## Palladium (Feb 14, 2014)

Lou do you have a link to where i could learn more about the science of making those? I've been wanting to try it for awhile, but the information i have found is sketchy at best. I would like to try it as a project just to see if i can do it.


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## Lou (Feb 14, 2014)

So far as I know, only he and I make these and him first.
I cannot give any details as he was the one to advise me on making them. They aren't easy to make and require patience and very good technique if the purity is to be absolute. They can be made pure enough to serve as reference standards for all refiners.

Here is electron micrograph of a platinum crystal facet.


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## g_axelsson (Feb 15, 2014)

I've managed to accidentally make some gold crystals, 0.3 grams of octahedral crystals, the biggest ones were up to 0.2 mm and clearly visible in a microscope... just need to work on that process a bit more to perfect it. :mrgreen: 

... gas phase transport, how hard can that be? :lol: 

Göran


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## Palladium (Feb 15, 2014)

I totally understand Lou. Not many people can do it and that's what makes me want to do it. 8) 
I've researched and understand the scientific principals of what the processes are, but not the intricate details one would need for a road map to experimentation. The journey continues!


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## goldsilverpro (Feb 15, 2014)

Besides all those occasional weird gold drops that look like gold paint, I made gold crystals twice in my life, but both times they were so small you couldn't pick them up. 

One time, I had a certain weak gold solution in a small porcelain, pan-shaped, butter pat dish, along with who knows what, and I looked at it several times a day, along with 50 other dishes, under a 100 power scope. Pure gold started to grow up into a gold fern. No joke. It grew branches that looked exactly like fern fronds. Over time, it got taller and grew more perfect fern branches. 

The other time, I was playing around, dropping gold with Versonal 120 from an aqua regia solution that I had added some acetone to (don't ask me why). Suddenly, gold paint. I dipped a glass slide into the solution to collect some of the crystals. Under a 1000 power ancient B&L Metallograph, after they dried, they appeared as perfect brilliant gold hexagons. They were so reflective from the metallograph light, you could hardly look at them without hurting your eyes.


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## g_axelsson (Feb 16, 2014)

The crystals I made I saved in a small glass petri dish. You can easily hear the tingling sound when they roll over the surface.

The crystals were made in a way I'm not too proud over but as it's a long time ago... here it goes.
Almost 30 years ago when I started experimenting with recovery of gold foils from contacts I just dissolved away the copper with nitric. I realized that the acid was worth more than the gold so I only did this as a way of testing thickness and composition of the material. Larger foils were picked up from the mass and properly cleaned and put into a beaker while the gray sludge (tin, as I later learned from the forum) were saved with all the small bits of gold.
Then one day I thought about mercury and that it would dissolve the gold. I added some to the clean foils and soon it started to dissolve, not as fast but eventually it looked just like liquid mercury again. Then what? I had no plan to how to separate the gold from the mercury. I've read about the potato trick but felt it was too dangerous so I just put it in a glass bottle with a glass stopper and there it sat until last summer.
As I didn't have any way to retort the mercury I finally decided to dissolve it in very weak nitric acid. Over a couple of weeks I slowly dissolved the mercury, the resulting liquid I could handle even if it was extremely toxic. After a week the mercury blob was noticeable smaller and started to become lumpy. Another week and it fell apart in a mercury colored sand and then a couple of days later it finally turned yellow.

I don't know if the crystals formed during the 25+ years in the mercury or from the slow dissolving of the mercury. Anyhow, it's not an experiment I will repeat, I'm done with mercury now and the poisonous liquids is taken care of.

Crappy picture of the crystals, but you can see the reflection from the crystal faces.



Göran


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## niteliteone (Feb 17, 2014)

We all have some skeletons in our past that we would like to stay there  
Are you able to add something to the picture for a size comparison :?:


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## Reno Chris (Apr 1, 2014)

Large crystal gold of a nature very similar to those pictured at the top of this thread are recovered with metal detectors in Northern Nevada at various locations in Pershing and Humboldt counties. These placers are commonly referred to as the "Rye Patch" area. Other mossy crystals and forms of crystalline gold are also found.


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