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FREQUENTLY ASKED QUESTIONS MINERAL COLLECTING

 

      How does one clean rhodochrosite?

      How can I stabilize a mineral specimen?

 

How does one clean rhodochrosite?

  Cleaning specimens probably is more of an art than a science. The least intrusive means of cleaning is better, but what techniques to use depend upon the minerals that you are trying to remove and what minerals you are trying to save.
I think that I would give water a little more of a chance. You might try soaking it for awhile and maybe try to use an ultrasonic cleaner or a soft brush.

CAUTION - it is best to test any cleaning procedure on a worthless specimen from the locality or a small piece of a larger specimen ( if it can be safely trimmed from the main specimen).

Before using oxalic acid, I would test it to see if it would dull the surface of the rhodochrosite.
You might also want to try acetic acid or citric acid.

Some good resources on cleaning are
Wright " The Complete Book of Micomounting" 1993
Pearl "Cleaning and Preserving Minerals" 1947 etc
Sinkankas "Field Collecting Gemstones and Minerals" 1988
John Betts article.


Roland Bounds wrote:
     Cleaning of the rhodocrosite may depend upon what you are trying to remove. If it is iron oxide (rust) there is a method which is pretty gentle and successful for use with most carbonates. It uses three chemicals; sodium citrate, sodium bicarbonate, and sodium disulfite. The only difficult chemical to get is the sodium disulfite, you will need to get this from a chemical supply house. The procedure is noted in several places -- an early issue of the Mineralogical Record is one, and I think it is also addressed in the Pearl book on cleaning and preserving minerals. This particular procedure is specifically for reducing and removing iron staining. I would not use oxalic as this would tend to kill any luster on the rhodocrosite, if it didn't dissolve some of it outright. 
 
How can I stabilize a mineral specimen?
      Desert "roses" are usually one of two minerals, either barite ( mainly found in Oklahoma) or gypsum. Both of these minerals are stable in a home environment and won't alter. I am making the assumption that your specimen is gypsum. It is usually not a good idea to coat a mineral ( except if it tends to gain water or dehydrate and is not delicately crystallized) as it usually would lower the value of the specimen. It takes a blow torch to dehydrate gypsum.
     If you are trying to strengthen the matrix of the specimen, a half Elmers glue half water solution can be used to impregnate the matrix ( this works especially with a limonite matrix). For strengthening the mineral's attachment to the matrix, one can carefully add small amounts of super glue to the base of the crystal. When doing any of this, be careful not to get any dust on the specimen, since it can look bad.
    The best way to preserve a specimen is probably to build a plastic case for it. This can keep the dust off the specimen and keep curious fingers away from it ( that is why they have cases in a museum). 

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