FMF - Friends of Minerals Forum, discussion and message board

[AleaBankston]

I have a small amethyst cathedral I’m looking to have aura coated and wondered if anyone could recommend where to have it done? I’m located in the US, so I’d like to have it done domestically. I also attached a photo of the type of outcome I’m hoping to achieve.

[Mathias]

Don't do it. It's screwing up of a beautiful mineral specimen.

[Bob Morgan]

That raises a question. How can such coating be removed? Years ago I was looking for quartz crystals with unusual faces. Behind the Days End Motel in Tucson there were large tables of crystals. The only interesting ones were coated. I bought a few but never got around to figuring out how to restore them back to natural.
Has anybody done this?

[AleaBankston]

[AleaBankston]

[eric8he]

Wouldn't bead blasting remove the "aura" coating from quartz? I think most metals commonly used as a coating have a hardness of 6 or less and can probably be removed with glass beads.

[James Catmur]

On a site like this, you will find people who like natural crystals and see treatments like that to be a travesty. Each to their own, but I suspect we cannot help you.

[AleaBankston]

[Pete Modreski]

Dear Alea,

As our list moderator James Catmur explained, this site, this Forum, though our title does not clearly explain this, is really aimed at mineral collectors who want to share information about mineralogy and collecting natural mineral specimens, so as James says, your question about getting an "aura" coating on a specimen is really quite "off topic" for our Forum--but as I say, there is not any way you could necessarily be expected to know this (without carefully reading our posted "guide for using the Forum".

There are no hard feelings about you posting your question to us, you understand; it's just "not what we are trying to focus on here". But regardless, since I am writing--as I had intended to, when I read your question--we all do try to be as helpful (and courteous!) as we can to any new posters who use this Forum, so I would like to try to give you a bit of an answer to your question.


Just to say, that the apparatus for putting these coatings on crystal specimens is quite complex and expensive, and not something that many companies have. It involves using a large high vacuum chamber, and using a special high voltage electrode to transfer atoms of the metal being used (titanium, gold, whatever) from the source electrode of the metal to the surface of the crystal(s). I don't believe there are very many companies that do this, and I'm sure that most only use it to treat their own specimens in bulk, for wholesale sales. (I have actually, quite a few years ago, tried making these kinds of coatings on crystals myself as an experiment, while using equipment to coat specimens for use in scanning electron microscopy--"just to see how it works"--you know, we scientists are always curious!)

If you search on google for some terms describing this you can find, as I just did, some information about companies that do such things, but mostly you will just find sources that are selling the already-treated crystals. I simply searched for "how to have aura crystal coating done" , but one site I found, you should be able to find it yourself by searching for "Aurora Crystals Azotic LLC". It is a place that offers to coat crystal specimens that people can send to them, and it gives a page of guidelines of what they can treat and what they can't, and instructions for contacting them (I was curious to see just what it said, and that there even was such a company, that would coat crystals "on demand"). I see that, among their specifications, is that the largest specimens they can handle are 7x5x5.5 inches. Their charge for doing this is "supplied upon request", but I think you will find, that to have this done is going to be quite expensive, and that just the cost of securely shipping your large specimen to and from the company, is probably going to equal close to what you may have paid for it.

I hope these comments will be of some help to you. I think you should be able to find all the information you need, by searching on the internet.

Sincerely, Pete Modreski

[AleaBankston]

[John Betts]

Nobody appears to have answered the question. The Aura crystals are created using vacuum vapor deposition of gold on crystals. Since the gold is a coating, it is removable.

Aqua Regia should dissolve the gold. Use with caution - Aqua Regia is a mixture of two acids.

[Bob Morgan]

Thanks John,
I'm actually dealing with a candy red coating. At this point Ive gotten better examples of the same crystallography and will probably not bother to try to remove anything.

[John Betts]

The red coating is described as titanium vapor deposition. According to quick search results: "Boiling concentrated hydrochloric acid will slowly dissolve titanium, forming a purple solution of titanium trichloride"

[Bob Morgan]

Thanks John, 'sounds like stirring a witches brew. I've cooked stainless steel in nitric acid. I'm assuming this is no more dangerous than that - avoiding fumes and neutralizing the solution and not pouring it on the food garden.

[lluis]

Hi, John

Agreed with you that is titanium coating..
That hydrochloric acid will take it out, well, maybe,,,,or maybe not...

I would suggest to treat with nitric acid, but that is dangerous (yellow stains in skin, as soft. Painful scars at worst....)

As always said, if you work with chemistry, let any chemist help you.... It is somehow dangerous if you do not know what you do...

With best wishes

Lluís

P.D.: maybe my English is very bad or even extremely bad, but I did understand that first poster would have an aura finish ... not to erase it....

[Riccardo Modanesi]

Hi to everybody!
Many years ago I was presented a fake amethyst quartz bought in Morocco by my girl-friend and her parents. I treated it with normal ethylic denaturated alcohol and... the paint got away! It's easy!
Greetings from Italy by Riccardo.