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Fake chrysocollas from Congo
  Index -> Incorrect classification and fakes

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PostPosted: Jun 13, 2023 10:19    Post subject: Fake chrysocollas from Congo  

Our friend Christophe Gobin sent us a review to publish in FMF Forum about some supposed malachites and chrysocollas from Congo that have been on the market since last year.

We publish all the information he has provided to us:

Hi all,

We have seen in 2022 some malachite and chrysocolla specimens from the Congo, marketed by some Chinese dealers. I received some of them and I immediately suspected that they were fake.
I am used to travel to the Congo and have been offering a lot of malachite and chrysocolla specimens from this country.

I asked Dr Federico Pezzotta from MCP laboratory in Milano if he could run some analysis. It was a long and tedious scientific study, of about 10 months. He concluded that they are fake. The malachite specimens have undergone a chemical treatment which has made it possible to modify its color in a stable way.
They are real malachites from Congo but it is not chrysocollas. The fake ones marketed by some Chinese dealers must not damage the reputation of the real malachite-chrysocollas that we saw in the past and if it can help some collectors not to be scammed.

So here is his report, it is confirmed they are fake.
Christophe Gobin

Chrysocolla 1.jpg
The chrysocolla coating is like a very thin layer on the surface of the malachite like one micron thick. There is no chrysocolla inside the structure of the malachite. In 28 years of Congo, I never saw this kind of structure of chrysocolla just coating the malachite like that.
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Chrysocolla 1.jpg

Chrysocolla 2.jpg
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Chrysocolla 2.jpg

Chrysocolla 3.jpg
Usually inside the combinations of chrysocolla and malachite specimens, you see the superposition of the layers of the chrysocolla and the malachite like for this old specimen (left).

Some pieces have some damages, and it is blue inside the damage. How is it possible when the thickness of the coating is only a micron or so. Except if we consider that they were damaged before the coating (right).
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Chrysocolla 3.jpg

Chrysocolla analysis 1.jpg
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Chrysocolla analysis 1.jpg

Chrysocolla analysis 2.jpg
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Chrysocolla analysis 2.jpg

Chrysocolla analysis 3.jpg
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Chrysocolla analysis 3.jpg

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