Micro-Art Gallery #1: Crystals

by Richard L. Howey, Wyoming, USA

Each image can be clicked with the mouse to view a larger one.

 I need to begin by admonishing myself for not following my own advice.  I keep telling myself and everybody else who will listen—label everything!  Well, the first image is indeed labeled—47A.jpg—but I apparently lost the note (or more likely, never wrote one) identifying this crystal.  I suspect—which means, it's a wild guess—that it's from a slide of sodium bicarbonate (ordinary baking soda).  I quite like it because it looks like a miniature glass tree to me.

Sodium bicarbonate

  The next three images are all from one slide of Ascorbic acid (Vitamin C).  I should mention here that all of the images in this article utilized polarized light, although not always with fully crossed polars.  These three images show the wide range of variation of crystal types which can occur with a single compound.  These variations can be a consequence of a multitude of factors: temperature, rate of evaporation, solvents, impurities, etc.  In cases such as these, it is not feasible to talk about a "typical" crystal type; however, there are, of course, other compounds that crystallize out in a quite regular, consistent, and "well-behaved" manner.  As I look at these three images, I am reminded of some others which I took of ascorbic acid which, because they were among my first, impressed themselves upon me as "typical" and I'll include some examples later.

Vitamin C

  The next image (Bicarb3) demonstrates that a very ordinary household product, in this case, baking soda, can produce wonderful results (in addition to relieving indigestion.  I like this image, because it reminds me of a strange metallic ground plant that is rather like a cross between a lichen and a liverwort.

Sodium bicarbonate ('Bicarb3')

 However, again, even such an "ordinary" thing as baking soda can produce some real surprises.  Another slide showed radically different forms and, in this case, I was rather reminded of a Navajo tapestry with its bright colors and feather like patterns against a background that emulates white sandstone.

Sodium bicarbonate ('Na_Bicarb1')

 In previous articles, I have mentioned the biological stain, Orange G, which is an important contrast stain and does have some fairly typical patterns of crystallization.  However, the micrograph which I have selected here is anything but typical and, in my imagination, conjures images of cosmic gas clouds.

Orange G

 In the two images below of Adipic acid, you will notice series of slats or elongated "plates" that are fused together in such a manner that the differences in angle and densities contribute to the wide variation in color.

Adipic acid

 What follows are not exotic scrapings of tartar from my teeth, in spite of the labeling.  The next six images I own to a painful experience—a toothache in the middle of the night.  Before I could get to the dentist to get some antibiotics and painkillers, I dosed my tooth with a small bottle of liquid toothache medication which fortunately I had on hand.  After the dentist finally got finished, I still had a bit of the toothache medicine left and made up a slide.  The medicine has benzocaine in it—a topical anesthetic—some dyes (why I don't know—I don't think the "proper" color is going to be a soothing factor in the middle of a toothache), a volatile solvent, and various "inert" ingredients.  (Another puzzle—why add extra stuff that doesn't do anything?)  As you can see in Image 1528, the polars were not completely crossed and the result is a pink background with delicate pastel hues emanating from the crystals. Images 1534, 1536, 1538 and 1541 are from different portions of the same slide and demonstrate the remarkable variation in crystalline form and texture which a compound can produce.  Some of these effects are, no doubt, due to those inert ingredients, so they weren't totally useless after all, although I seriously doubt that the manufacturers were thinking of us amateur microscopists when they dumped this stuff in their elixirs.  Images 1529, 1534, and 1536 have a certain whimsical quality that reminds me of some of the paintings of the Swiss artist, Paul Klee, who often gave his creations delightfully playful titles, such as, "The Twittering Machine."






'Liquid toothache' medication ('Crystals_tooth' images)

 Perhaps, that's what I should do, go back and rename all my images using imaginative titles and then "Crystals_tooth1541" could become "The Pain of the Toothache from Hell".

 The Ferric ammonium sulfate image surprised me most pleasantly by the combination of the subtle colors and forms suggesting a view through a kaleidoscope.

Ferric ammonium sulfate

 I like each of the three images of Potassium phosphate for quite different reasons.  The K_phosphate image might be seen as a snapshot of some subatomic event occurring in the deep magnetic recesses of a giant particle accelerator and K_phosphate 2494, an image of the same event a nanosecond later.  But, of this series, K_phosphate 2492 is probably my favorite, for it suggests a crystalline butterfly in an alien landscape with three blades of grass.



Potassium phosphate

 Sometimes quite beautiful effects can be achieved by mixing certain substances. [CAUTION! Always be sure you know (not just guess) what the reaction of the compounds will be so that you don't end up producing a poisonous gas or an explosive substance.] I already mentioned that some chemicals can produce surprisingly different results from one slide to the next.  We already saw one image of sodium bicarbonate crystallization (Image Bicarb3) and how different it is from the image on  another slide (Image Na_Bicarb1).  However, the next five images are a nice demonstration of a successful mixing of two chemical which produce some unusual and striking results.  You will notice that in these five images, the general crystal patterns resemble that of Image Bicarb3 much more than that of Na_Bicarb1. Sodium silicate (NaSiO4), which I added to the sodium carbonate, is popularly know as "water glass" and used to be used as an egg preservative.  Sometimes, it can still be found in a local drugstore.  I have mixed it with a number of substances and with varying degrees of interesting results.  It tends, as it dried, to produce a cracked surface, which can result in both fascinating and dismal effects.  It should be handled with some care, since it is an irritant.





Sodium bicarbonate - sodium silicate mixtures

 A technique frequently used and discussed as a means of producing especially fine examples of crystallization is that of "melts".  This involved placing a bit of a compound on a slide and heating it carefully until it melts and then placing a clean cover glass over the crystals.  I only recently tried this method and with only 3 different chemicals.  I was making some micro-pipets and decided to try a few crystal melt slides as well while I had my alcohol lamp out.  I made 2 slides of each compound and the results were dismal except for an ascorbic acid slide to which I had added a small drop of water before heating.  I didn't like using an open flame so, in future, I will attempt making such "melts" using a small electric laboratory hot plate which I have.  The great advantage of this device is that it has a calibrated dial that one can set  for different temperatures and some crystals produce dramatically different crystallization patterns at different temperatures—copper sulfate, for example—so one should keep careful notes. The two images of melts below are ones which I took from slides which my colleague, friend, and adviser extraordinaire on things microscopical, generously gave me, Mr. Nik Berrong, owner of Rocky Mountain Microscope Corporation.



 Finally, I include three images of Vitamin C.  These were prepared by dissolving a commercial Vitamin C tablet (with all its inert goodies) in water and letting it evaporate in air without any heating of the slides.  (I just took some additional pictures using chemically "pure" ascorbic acid, but I'll save those for another gallery.)  Image Vitamin C-2481 shows a wonderful pastel swirl that seems to appear fairly frequently in Vitamin C preparations.  I included a black and white image as well to show how sometimes such an image can heighten contrast and reveal detail not visible in a color image.  The final image, I include because  the double crystal conjures for me a vision from above of two heavily feathered dervishes whirling away in some odd pastel world.



Vitamin C

All comments to the author Richard Howey are welcomed.

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