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Techniques for CollectorsInterseting website

29th May 2012 17:19 UTCRon Layton

I thought this would be interesting to those who do their own analytical techniques. Blowpipe

30th May 2012 20:06 UTCDonald Peck

Interesting web site, Ron. In the last few years, I have used an aquarium air pump attached to a blowpipe with tygon tubing. It works well with an alcohol lamp.

31st May 2012 01:44 UTCSteve Hardinger 🌟 Expert

A traditionalist would say the aquarium pump is cheating.

31st May 2012 15:32 UTCDonald Peck

That may be, but I don't get cross-eyed or pass out! :)-D

31st May 2012 17:02 UTCSteve Hardinger 🌟 Expert

A blowpipe analyst and politician both develop the same skill with experience: The ability to provide an endless stream of hot air.

1st Jun 2012 05:39 UTCRon Layton

If you click on Assaying and then click on Microchems you'll see a list of elements at the bottom of the page. Click on any of the elements and some very interesting photos of chemical tests in the process are shown. There are some other interesting things in this site such as well such as the "toothpick assay". I like the aquarium pump idea, too. No more seeing spots and hearing the angels sing.:-)

2nd Jun 2012 19:42 UTCJohn Attard Expert

Steve,

I like your comparison of blowpipe analysts and politicians!

Now, regarding burners. By far my favorite is a propane burner that one can buy from anywhere in the US with a tip by "Benzomatic"

There are various kinds but if you decide to go this way I suggest to get the one that is NOT self igniting because that one though more expensive does not produce a pointed and controllable flame for experimental.purposes. To obtain the luminous flame you may need to partially close the airhole with some Al foil. The burner is a very versatile tool for all things not just mineralogical.

John Attard.

2nd Jun 2012 21:42 UTCHoward Heitner

19th century mineralogy books contain extensive descriptions of blowpipe tests, particularly for metallic ore minerals. In some cases, the final result was a metal bead. Anyone attempting to duplicate these results with a propane torch may have some difficulty. Those original workers were using "water gas", a mixture of hydrogen and carbon monoxide, which is a much better reducing agent than propane or methane, which is the main component of "natural gas" used in North America and Europe.

2nd Jun 2012 23:36 UTCJim Robison

Howard

It has been too many decades since I last used a blowpipe, although I still have one. My recollection, upon reading your comments, was that a bunsen burner - which I used - based on natural gas (methane) worked quite well for either oxidizing or reducing tests. Don Peck's book on Mineral Identification has a good clear explanation of the various parts of the flame profile, and I do not recall much difficulty, with a little practice, in being able to generate either an oxidizing or reducing flame by aiming the blowpipe tip into the appropriate part of the flame, and by manipulating the position of the test sample in the blowpipe flame. Use of a small charcoal block also greatly enhances development of a reducing environment when needed.

The reference on blowpipes at the top of this thread includes an excellent e-booxs citation to an early (1850's) comprehensive manual of the use of a blowpipe. I couldn't get the figures to come up, but the text is imminently readable.

I haven'd used a propane torch, but suspect that with practice a user can also develop a clearly defined flame profile allowing the proper test flame.

3rd Jun 2012 07:15 UTCJohn Attard Expert

Howard,

As far as I know "water gas" was never supplied to the public as town gas because its 50% CO was understandably considered too toxic. Many places including the labs that these workers used was coal gas; granted that this probably varied from place to place.

Back to use of propane you would be surprised how good a reducing agent it is used with the blowpipe over charcoal. One may mention that the species in the flame may not be propane itself but highly reactive species generated from it.

3rd Jun 2012 10:30 UTCBart Cannon

The third mineral book I bought was:

"Identification and Qualitative Chemical Analysis of Minerals"

Orsino C. Smith, Van Nostrand, 1953.

It has lovely color plates showing the sublimates from blowpipe tests of various mineral elements as well as borax beads..

Plus details on circular breathing.

Bart

6th Jun 2012 01:50 UTCEugene & Sharon Cisneros Expert

Bart,

The attached photo shows how I developed my circular breathing and blowpipe technique.

Cheers,

Gene

6th Jun 2012 07:13 UTCRock Currier Expert

Gene,

Don't use your technique on micromounts. It is only good for boulder size specimens.

18th Jun 2012 01:56 UTCHoward Heitner

I remember being very frustrated try to use an alcohol lamp, many years ago. Perhaps propane and methane flames are better reducing agents. Most of the unknowns, I bring home from the field are silicates. Other that trying to determine fusibility, the blowpipe is not very useful for them.

Water gas was delivered to homes in many countries, before the 1940's. Putting ones head in the oven was a common method of committing suicide.

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