Jewelry sample testing - Assaying - Assaying, Microscopy, Mineralogy & XRF/XRD - Metallurgist & Mineral Processing Engineer

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Jewelry sample testing - Assaying (5 replies and 3 comments)

2 years ago

I work for a jewelry company and want to get a full analysis of the metals we use. Them being stainless steel alloy, 10k, 14, and 18k. Gold. I was recommended to use a fire assay but after asking around I notice companies require at least 30g of samples.

Would a fire assay be the best method to get the information I need? If not, is there another method?

David

2 years ago

David 2 years ago

you don't need 30g for a fire assay

NolanGoddard@actlabs.com

Mike

2 years ago

Mike 2 years ago

1 like by David

It should be noted that a fire assay is a distructive test, you do not get back your original material. What you get back is a gold slug for each grade that is close to 99% gold. If you want to maintain your original material then you need to look at x-ray flouesecence (XRF) which is close to a non-destructible examination (NDE). XRF can be used on almost any metallic material to determine the assay.

Also how often will you be doing this? If only once then an outside lab is fine. Otherwise you might want to look at getting a handheld unit for your shop (can be expensive, but then so is regular testing).

bezelsunl

2 years ago

We have a handheld x-ray device but we need a more accurate process that tells us exactly what metals are there. We want to replicate and manufacture these pieces using raw materials.

bezelsunl

2 years ago

We don't mind losing the original material. This would be a one time job to find out the chemical makeup so that we can manufacture them.

David

2 years ago

David 2 years ago

A typical fire assay is 30 g for feed grades.

If it is a concentrate or high grade we can do as little as 5 g

As Mike says, the best for no losses is an XRF.

bezelsunl

2 years ago

We don't mind the loss of material as long as we get a full chemical make-up.

Mike

2 years ago

Mike 2 years ago

Fire assays are not 100% accurate, especially for determining specific concentrations. For that a gas chromatograpy would give greater precision.

DAlchemist

2 years ago

DAlchemist 2 years ago

Conventional Fire Assay would not be the way to determine the metal content of your jewelry. The fusion of the sample ideally slags off non-precious metals, although some nickel and copper may report to the lead button. However, your next step, cupellation will take care of those base metals. The prill once digested will be void of silver and only Au, Pt and Pd will remain.

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