Telescope Reviews: Just a few ?'s

Hi Todd!

A good 10x loupe is a must. 10x is of limited use on the night sky, but it works wonders on meteorites and minerals. Surplus Shed sells a cheap $6 doublet 10x loupe that works decently well. On the higher end, Nikon and B&L make superb triplet loupes that are about $100. I found a comfortable middle road with a Belomo 10x triplet loupe I got on eBay for about $30. Works great and it opens up a whole new way to appreciate meteorites - especially the ones that have been sliced open to reveal the matrix for study.

Generally speaking, with microscopes and loupes, low power is best for most general work. My stepson repossessed the microscope I had on loaner, so I am currently limited to my loupe. But when I did have the microscope, I rarely went over 100x. Also, to fully appreciate a meteorite under the microscope, a "thin section" is needed. This is a prepared slide with a super-thin slice of meteorite on it. It allows light to pass through and it will reveal much more under magnification than a more substantial chunk which won't allow light to pass. Cross-polarized studies can also be done with a loupe or microscope and this is usually what produces those spectacular color photos you see of meteorite interiors under magnification. All you need to do this is a couple of polarizer filters (like the type used on cameras), a bright light source, and a loupe/microscope.

The way I figure, any microscope is better than no microscope when it comes to meteorites. So I currently have my eye out for an inexpensive used microscope - possibly from eBay. The older Tasco models from the 1950's and 1960's were made in Japan and have fantastic optics compared to the "student" microscopes you see offered today. These older microscopes (which typically come in a wooden storage case) can often be found in superb condition for under $50.

Slicing is best done with a diamond blade or a diamond wire saw. The thinner the blade the better because it destroys less of the meteorite. A wet-saw is a must. You can even use a wet tile saw, like the type used to cut ceramic tile. But the blades are thick and it chews up a lot of meteorite in the process.

Etching is accomplished by bathing a polished surface of iron meteorite in nitric acid or nitol. The process is discussed (and shown) in a thread in this forum here :

http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/2306720/page/0/view/collapsed/sb/5/o/all/fpart/1

Regards and clear falling skies,

MikeG

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Michael Gilmer - Member of the Meteoritical Society & Collector of Falling Stars.

Galactic Stone & Ironworks - Buy/Sell/Trade Meteorites, Moon Rocks, Mars Rocks, & 35 different falls and types!