The BelOMO 20x Quadruplet Loupe Magnifier has a viewing area of .28" (7mm), much larger than the Bausch & Lomb Hastings 20x Triplet Magnifier. The large .5" (17.5mm) 4 elements gather lots of light to provide this quadruplet loupe with a bright and clear view.
The following details are true of any lens such as a loupe magnifier, microscope, telescope, camera lens or other high magnification lens.
A 20x magnifier should NOT be the only magnifier you own. It's just too much magnification for normal usage. For instance, if you're using it to look at newsprint you would see at most a 4 letters at a time.
Must you have such strong magnification?
You'll be incredibly close to the object you are examining. Almost touching. For a 10x the focus distance is around 3/4'' but for a 20x it's about 5/16''.
The 20x power magnification provides a very strong level of
magnification which works best on flat objects like coins or stamps or surfaces of objects.
However, only a small area (field of view) will be visible. Think of examining a quarter and all you can see is the date but it's highly magnified.
The stronger the magnification means the less depth of field the lens will have. Depth of field is the vertical relief that appears in focus on an object having an irregular surface like a rock or mineral. You'll have to ''dance'' the lens around more on rocks and minerals but the portion of the object you're viewing will be highly magnified. The limited depth of field also make a 20x the most magnification you'll want to use when hand holding a loupe. With a higher magnification the slightest movement in you hand will cause the image to continually move in and out of focus.The high magnification works well when you need to closely examine the surface of a rock or mineral, the surface of a gem for minute scratches, small areas of coins and stamps or any other object where you need to examine a small area under high magnification. It's great for reading laser inscriptions on diamonds.
The larger size of this lens compared to other 20x loupes means it will capture lots of light for a very bright view. This is also a loupe that you can hold comfortably in your hand unlike the smaller than a dime lens from Bausch & Lomb.
The housing and cover are machined metal and coated with a matte black finish and assembled using flathead screws. Belarusian Optical and Mechanical Association (BelOMA), makers of sights for guided weaponry, camera lenses, and other optical components manufacturers these loupes.
Highly recommended by the Amateur Geologist. The BelOMO loupes are the loupes we always use though it's the 10x that we typically carry in the field. If you MUST have 20x power then this is a great lens to have.
Don't let this price fool you. The BelOMO loupe is a FANTASTIC buy. These are quality lenses that stand on their own against the higher priced competition. Take advantage of the recovering Belarus economy and a military supplier finding other revenue streams in a capitalistic market.
Each BelOMO loupe we ship is custom treated to prevent the screws from coming loose with usage.
Heavy duty 3/4'' plain black nylon loupe lanyard with a quick release buckle and a split ring. This lanyard may be used for any purpose but we've had it custom manufactured specifically for use with the BelOMO loupe.
Important: We offer this lanyard for no additional charge when you buy the combo package of the BelOMO loupe with attached lanyard. Attaching the lanyard requires a screw to be removed so let us do it. We've been doing it for years and you save money!
Use the split ring on loupes with a mounting hook. To use the lanyard with a BelOMO loupe remove one screw on the support shaft of your BelOMO loupe, swivel the frame out of the way and slide the end over the support shaft then install the screw again. Don't use the split ring to attach the lanyard to the loupe. (We suggest that you purchase the loupe with the lanyard already installed.)
Minerals of the World is an attractive and up-to-date guide to more than 500 minerals from around the world. The succinct text--covering crystallography, properties, names and varieties, structure, diagnostic features, and occurrence--and the discussion of less common minerals not found in other guides make this an invaluable resource. With over 600 exquisite color photographs and crystallographic diagrams, this book is unequalled. It is set to become the field guide of choice for mineral collectors and students of mineralogy.
Inside the front cover, Robert Hutchinson writes:
It began innocently enough. While photographing the Painted Desert, Atkinson became intrigued with the brilliant colors in the petrified wood scattered on the ground. He brought home some polished rocks, photographed them under glare-free lighting, and was captivated. The photographs looked more like paintings of forgotten dreams than either rocks or photographs. Atkinson proceeded to photograph thousands of art-quality polished rocks, bought or borrowed from international dealers and collectors, and to refine his photographic techniques.
From these thousands of photographs, Atkinson has chosen for ?Within the Stone÷ seventy-two that have yielded the most striking, the most poetic, and the most ineffable images. Atkinson opens a vault beneath our feet, revealing to our astonished eyes the tumult of color, form, and desire hidden ?Within the Stone.÷ He invites us to enter the dreams of Gaia. Some of these are epiphanies so far removed from our mundane experience as to beggar ordinary language and analogy.
Seventy literary pieces were commissioned for this book from seven writers. Every one of the writers has conspicuous attainments in both scientific and artistic modes. Each writer was asked to free-associate with his or her ten assigned photographs as though they were high-level Rorschach patterns. The seven contributors are Diane Ackerman (poet and psychologist), Philip Ball ( Nature editor and dramatist), John Horgan (science writer and philosopher), Andrew Revkin ( New York Times reporter and Hollywood screenplay writer), Dorion Sagan (science writer and novelist), Tyler Volk (NASA biologist and architect), and David Zindell (science fiction novelist and mathematician).
In an appendix, mineralogy experts Si & Ann Frazier and Robert Hutchinson provide mineral commentary for each specimen.
In this book two renowned experts share their lifelong passion for geodes and their extensive knowledge of world-class geode deposits as they present the latest theories on the formation and occurrence of these amazing mineral gifts of nature.
The most comprehensive book ever written on geodes of the Americas - a definitive reference for serious collectors and a delightful mineral exploration for both experts and novices.
The Mineral Hardness Ruler is a stimulating visual aid, educates in one phase of mineralogy, and provides the standard ruler measurement scales needed in classes.
Rockhounds, mineral enthusiasts, students, teachers, geologists, and any one interested in rocks and minerals will find the Mineral Hardness Ruler a handy visual aid for quick information on mineral hardness.
The two-sided, flexible, glossy, vinyl ruler consists of five scales: three measurement scales and two mineral hardness scales. The measurement scales are in standard ruler measurements of tenths of inches, sixteenths of inches, and millimeters. Mohs' relative hardness numbers are integrated into the inch scales, while a separate scale exists for an absolute mineral hardness scale by Rosiwal.
On one side of the ruler are pictures of the ten common minerals, in full color, selected by Mohs for his relative hardness scale. On the reverse side of the ruler are six common items with their relative hardnesses. These items, along with known minerals, can be used as a handy field kit to test the relative hardness of an unknown mineral.
Hardness is one property of a mineral that can be used to distinguish among similar minerals. A given mineral can scratch any other mineral of the same or softer hardness. Over a hundred years ago, the German mineralogist Frederick Mohs devised the relative hardness scale that has found favor with mineralogists for over a century. Others, such as Rosiwal, formed absolute hardness scales using the same minerals as Mohs. For example, diamond, the hardest substance in Nature is not twice as hard as apatite, 10 versus 5, but over twenty thousand times as hard, 140,000 versus 6.5.
The Deluxe Moh's Hardness Pick Set now comes in two case types. The wooden case is small enough to carry and the top screws into the base to make a perfect desk stand. The plastic case is longer but the thinner size makes it easier to carry in your field tool set.Hardness is an important and quantifiable physical characteristic of a mineral and in your effort to identify an unknown mineral, the hardness, if known, combined with other properties, can narrow your search to just a handful of possibilities. Simply scratch a smooth surface of your unknown mineral with the picks of various indicated hardness. As an example, if a No. 5 pick scratches the mineral, but a No. 4 pick does not, then your mineral hardness is 4.5. Then compare this against a table of minerals listing hardness values to aid in identifying the unknown mineral.
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