Is this ore/rock Platinum, Palladium & Rhodium?

A. Charles,

Why don't you go to a local Assayer ... presuming/hoping that you have one in your neck of the woods.

An 'assayer' is nothing more than a mining chemist ... but would have/should have all the testing equipment to determine what you sample might be.

... and if it's solid Platinum, please contact me IMMEDIATELY! I'd like to get some shares!

Freeman Newton [deceased]
R.I.P. old friend (It is our sad duty to
advise that Freeman passed away 4/21/12)

A. Look for a metallurgy lab around, they will analyze it for a decent price.
Guillermo Marrufo
Monterrey, NL, Mexico

A. It will cost you a good bit of money to have it analyzed by spectroscopic methods.
While anything is possible, I doubt if you found a "chunk" of any of the precious metals that you mentioned. If it is, I would be looking for more, before someone else finds it.
My guess is nickel or cobalt. Put a drop on pure nitric acid on the brightest spot. If it turns green it might be nickel. If it turns a blue or purple, it probably is cobalt.
You might put the whole rock or part of the rock in swimming pool acid to see what happens. Some kinds of rock dissolve and others do not. Some metals will dissolve and others will not. Save the solids in a vial and the acid in a plastic container for possible later analyses.

A. Avoir du pois ounces?
Probably all three or else none if it's truly natural. Description of native metallic platinum:
"Platinum is usually alloyed with several percent Fe and with smaller amounts of Ir, Os, Rh, Pd; also, Cu, Au, Ni...[Specific Gravity] 21.45 when pure, 14-19 when native. Malleable and Ductile. Color steel-gray, with bright luster. Magnetic when rich in iron."
-- Manual of Mineralogy, 21st Edn., page 340, ISBN 0-471-57452-X.

1) Hang by a string and check with a strong magnet for attraction. A very weak attraction is good.
2) Determine the specific gravity. One method is the Jolly balance (ibid., p. 257): Hang the specimen by a fine wire from a spring balance. Weigh in air and then submersed in room temperature water. The difference gives the weight of water displaced and hence the specimen volume. Higher weight is better.

3) Heat with an ordinary propane burner. Nothing should happen (oxygen is also required for melting). Poisonous fumes or burning are not-so-good. Possibly, a jeweler friend familiar with casting can try melting in a ceramic crucible. The higher the melting point the better; Pt & Rh have considerably higher melting points than the cheaper Pd, but expect alloying to lower the m.p. by as much as 200 °C.

4) Have a laboratory analyze the composition using an SEM equipped with EDS analyzer (EDAX). Ask for at least 5 points on each of 2 sides, plus photographs of elemental distributions, and a signature on the report. Nice to know; necessary for selling.

The wet chemistry & pyrometallurgy of assaying and refining the platinum group metals involves strong acids, including aqua regia, and thermal decompositions giving off toxic gases such as SO3. Just a hint: Nitric acid will dissolve only Pd and the less noble impurities, aqua regia will dissolve both Pd & Pt, while the residue after aqua regia leaching can be fused in molten anhydrous sodium bisulfate ca. 315 C to form rhodium sulfate. Solubilize, filter, precipitate, dissolve, precipitate...thermal decompose. Several such purifications give finely divided metal powders which can then be melted by electron beam in vacuum. So, skip the chemistry -- you might take it apart, but not be able to put it back together (in separate parts).

High hardness is expected, multiple alloying components may raise the hardness by 3x. Can't say much except soft is bad (unless have a nearly pure metal), maybe a sign of lead, silver or mercury.

5) With results 1-4, you can fill out a request to quote from a reputable company to whom you would mail the material, and receive payment after the assaying and refining costs are subtracted. Use an established company listed on a stock exchange (NY, London or Toronto).

Good luck.

A. Hi Billy. The easiest first step is to determine its density or specific gravity. Weigh it, then immerse it in water and weigh the water it displaces. The specific gravity is the weight of the item divided by the weight of the water it displaces. Alternately, Ken Vlach offered a good method of weighing on a spring balance in air and then in water. Good luck.
Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. Hi Billy
Platinum melts at 1770 °C - way hotter than any other common metal. You might just be able to melt a small piece with oxy/propane but oxy/hydrogen or an induction furnace is more usual.
My second point is that platinum is very high value. People don't just lose pieces in a river.
Natural alluvial platinum occurs in Colombia and the Ural mountains of Russia. Finding a piece in Arizona seems unlikely.

Geoff Smith
Hampshire, England

A. Hi. It's not platinum because that would be more than three times heavier. It's quite unlikely, but perhaps not impossible, that it's a silver alloy -- which you could test with a relatively inexpensive kit. It could be tin. But if I was forced to bet on a guess, mine would be that it's discarded zinc, which would be pretty cheap. It still might be worth bringing to a scrap dealer if one is local.
Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. Maybe Chromium.
Kaktusz Ranch
- In the middle of nowhere, California
August 30, 2022

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A. Hi,
it will be better if you test your ore in any certified metal testing lab.
bhupesh mulik
refining consultant - Mumbai, India

A. Hi Chris. As Bhupesh has suggested on this page, the best first step is probably to have the material tested by a metal testing lab, which you can surely find with google. This, however, will cost you some money. The next step is probably to find a refinery, again with google.
If you know enough chemistry and have had enough training to proceed safely, you can probably read some refining texts and do at least some preliminary assessment of what you have.
Luck & Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. If you will provide me with a dime sized specimen I will run a scan for you without cost. The XRF results will give you an indication of whether or not you have something of value whether or not you should follow-up by sending a sample to a mineral lab for a certified analytical test. Certified tests cost money but they provide you with very precise and detailed info concerning the chemical makeup of your specimen. There are a handful of labs in the western US and Canada that can do this for you.
Kurt Kephart
- Billings Montana
August 24, 2022

A. Hi. I can think of three choices, but there may be others --
1. Take it to a "We Buy Gold" store and see if they want it, but they probably won't :-(
2. Pay to have it analyzed.
3. Sell it cheap to the person who thinks it is rhodium :-)
Sorry, but rhodium doesn't come in the form of chunks or nuggets like gold.
Luck & Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

Hi Glyn. Ken passed away several years ago, but rhodium isn't blue; and isn't present as independent metal but only as a very small percentage of the total precious metal, which is itself only a few grams per ton of rock :-)
Although I suppose that nothing is impossible, please be careful to not let anyone scam you.
Luck & Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

! Hi Glyn,
I am curious as to where your searches have taken you with the blue RHODIUM and other precious metals that the XRF has detected. I'm in the same boat with not much info to proceed with. My XRF didn't detect but a trace of gold, but was high in all other pgms. I had it retested 3 weeks later with same results. Just curious if you have any insights as to separation, assays.
Thanks again.
Kelley Higgs
Hobbyist - Portland Oregon

Lunar Meteorite

A. Hi Rajesh. Did the person who suggested it is a lunar meteorite have some qualification to make such a suggestion?
On the one hand it's certainly possible that it's a lunar meterorite! But on the other hand I've visited rock museums many times, each with more than 5,000 specimens on display, and every one of which looked really unusual to me ... but each of which were naturally occurring on earth. So, "looking unusual" is no indication of extraterrestrial origin. Sorry, I don't know an inexpensive way for you to find out :-(
Luck & Regards,

Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey

A. Please send the sample to Physical Research Laboratory, Ahmedabad, Gujarat, India. They have done extensive work on meteorites, lunar samples etc. They would be happy to throw some light on this. You may also contact Geological Survey of India.
Prabhakara HR
- Bangalore, Karnataka, India

A. It looks kinda like space nickel. I had some it was heavy as hell like a metallic grey color I took a grinder to it to see the cut away and it was surprisingly soft and hard to really cut because the heat from the grinder kinda soften it. Anyways I gave a friend a piece he took it to a pawn shop and got 90 bucks a gram for it. I thought it was palladium just nickel from space that was somehow formed in an environment with no oxygen
Dee S [last name deleted for privacy by Editor]
- California
September 23, 2022

A. Hello Jeremy,
It's very hard to determine metal(s) from a photo. If you want to invest some cash and have it assayed, that would give you a concrete answer. As far as anyone getting $90 a gram for "space nickel" at a pawn shop, I'll be the next one on Jeff Bezos' rocket and have my net out.
MARK BAKER
- WINSTON SALEM
September 27, 2022

? Hello, did you find any answer, I have the same ore. It is NOT affected by any acid, but with potassium chloride and ammonia it turns red.

A. Hi Tommy. It's a very pretty rock, but what would lead you to believe that it might be rhodium? I'm no rock expert but I'd guess it's iron pyrite or galena.

While I doubt that anyone can say that there is positively zero rhodium in a chunk of rock based on a photograph, if you picked up ten thousand pieces, the odds of finding a fingernail size sliver of rhodium would still be nearly zero. Rhodium is so rare that even when its value is $20,000 per ounce no one can afford to try to mine it; they only get it as a small byproduct when refining platinum :-(
Luck & Regards,


Ted Mooney, P.E. RET
Striving to live Aloha
finishing.com - Pine Beach, New Jersey