My Inimitable Field Gear: No. 2

One of my favourite quotes, I used three decades ago in my opening for Speech Project No 4 at a Toastmasters Club, goes like this, “A stupendous creation surrounds us, with infinite form, infinite variety and infinite beauty. The more intense our awareness of this vast complexity, the more alive we are.”

We geologists are indeed very lucky, as it is in our education and professional practice to see a world in a grain of sand. How do we appreciate this? By using of a good hand lens.

While common folk step on, or kick a piece of rock, we geologists use hand lens to see the minerals that form them, the unique crystal system that identifies them, and think of the complicated processes that created them. There is so much to see and discover in a small piece of rock specimen, like the various textures, crystal shapes, and the play of light that gives brilliant colours. Helen Keller was once asked of what she thought was the worst calamity that could befall a person, she replied, “To have eyes and fail to see.”

Speaking of finding a world in a grain of sand, imagine the millions of people who've been to the beach many times, yet fail to see that every wet grain of beach sand is thinly coated with water and does not actually touch each other. This is the reason why beach sand is never ground to powder, no matter how much they are pounded by waves. “To be a geologist and fail to see? Nah… it never happens, we are equipped with a hand lens.”

The hand lens has many names, like pocket lens/glass, magnifying glass, loupe, lens or 10X. Whatever called, its purpose is to aid our naked eyes to see things that are beyond our normal vision. With the many names, come the various types, styles, brand and prices. So what is the best lens for geologists? There is no one answer, but here are a few technical specifications I have used that proved to make a good choice.  I may be biased, but one lens that has travelled and grown old with me is my 10X and 20X Hastings Triplet, made by Bauch and Lomb (see photo).

Here are the things to look for: First, construction. The Hastings Triplet is built from three separate high quality lenses bounded together to form a compound lens. This compound lens provides very distinct image that is highly corrected for spherical aberrations. Second, lens quality. The lens should be of high quality material and polish, specially coated and corrected for chromatic distortion to give true colours. Third, magnification. This commonly comes in 7X, 10X, 14X and 20X. I prefer 10X as my prime all around lens as it gives me just the right detail and good field of view. Should there be a need to see finer crystal forms, then 20X comes in handy. Fourth, body construction. Should be rust proof or hard plastic. It is also best that the triplet lens is waterproof. Water should not get in between the lenses.

One more thing, when carrying your hand lens around your neck, the choice of lanyard is very important. For safety reasons, choose a lanyard that is breakable, not one so strong that when it gets caught will choke or even hang you to death. “No, I am not speaking through experience here, and don’t have the rope burns marks around my neck to prove it.”

[Originally Published in GeoFalcon, Issue No. 3, November 2013]