by Ron Hartman of Ron Hartman Meteorites
AN INTRODUCTION TO METEORITES AND METEORITE COLLECTING
I. PREFACE TO THE SERIES
When offered the task of writing a series on meteorites and meteorite collecting for newly interested collectors, and anyone else who May find this series of use to them, I first thought of the two Martian satellites (note the meanings of their names…fear and panic!) The science of meteoritics draws upon the sciences of astronomy, geology, chemistry and physics. For the young or beginning collector, the maze of technical terminology and complex explanations encountered May seem to be overpowering! Fortunately, there are a number of excellent web sites (and more seem to come into existence all the time), set up by both collectors and professionals, as well as books at many different levels, that offer excellent information.
Many years ago, my Professor in Meteoritics at U.C.L.A., the late Frederick C. Leonard, gave me his personal copy of one of his books…a rather comprehensive treatise in Mineralogy. He had written in the margin, “A simple subject made difficult”. I shall draw from that thought and try to make the content of these articles simple, useful, and enjoyable rather than intimidating and overwhelming! I hope (and believe) everyone will find some things of interest in this series. I can guarantee that as we get into the “meat” of the content, that there will be something for everyone.
Meteorites are the rarest of collectibles, and certainly among the most esoteric. Most meteoroids will fail to survive their passage through our atmosphere, and, of those that do make it to the Earth’s surface as meteorites, intact or as fragments, most will deteriorate and be lost before being found and recognized.
We, who live in countries where meteorite collecting is permitted by law, are most fortunate. We sometimes complain about not having access to searching (or keeping what May be found) on government property. (Laws tend to give ownership of meteorites to the landowner of the property on which they are found, so legally and ethically, one should obtain permission to hunt on anyone else’s land). In some countries, such as India, private ownership is forbidden. All meteorites that fall in (or rather, onto) that country must be archived for scientific study. Even cutting dust is inventoried! The lucky finders gladly turn over any finds to the government (it is said). Elsewhere, meteorites are sometimes exported only with difficulty.
Those of us who have spent many years searching, collecting, trading, and studying meteorites tend to sometimes forget that meteorite collecting is still a process which is essentially unknown to and not well understood by the great majority of the population. There are even teachers, whose students May profit educationally from being able to directly examine a meteorite, who are not aware that inexpensive specimens May be had. (Many dealers do donate specimens for education in an attempt to solve this dilemma!) My personal license plate ‘METEOR 1’ attracts considerable attention. The most common comment I hear from people passing by is “Can someone REALLY collect meteorites?” I hear the same from neighbors and acquaintances in everyday conversation, as well. That question is usually followed by “How do you KNOW it is a meteorite”? (Sometimes followed by a giggle or two!) Of course, I need not even comment on replies one gets when showing someone a Lunar or Marian specimen (…and, of course, just forget about mentioning that you have a piece of the asteroid Vesta!)
The purpose of the series will not be to discuss specific named meteorites, except for illustration. I hope to focus on one specific area of interest each month. One of the topics will deal with the proper methods for searching and documenting a meteorite find (everyone wants to actually FIND a meteorite or two and to know how to go about doing it). There is a right way, and a wrong way, and the wrong way can, in fact, destroy some of the science we want to preserve. (I would hope that a responsible collector would want to have sufficient respect for the science to do whatever it takes to assist in the accumulation of data, whenever and where ever that opportunity might present itself.)
Another topic, one about which I have had many inquiries, will address the proper maintenance of a collection (with proper care of both irons and stones to prevent them from becoming “rustballs” down the road!). It is desirable that collectors understand the properties of the meteorites one is collecting, and just as important, to know how to take best care acquired specimens. It is sad to see how many expensive meteorites are sent to my son Jim’s restoration service that had been either completely destroyed or were well on their way, primarily due to neglect! Surprisingly, some apparent “rustballs” can even be saved if attended to correctly. Some cannot!
A discussion of the characteristics and classification of different kinds of meteorites is especially appropriate with so many very affordable rare varieties currently coming out of Northwest Africa (NWA) and elsewhere, and becoming available in the marketplace. We are witnessing the great global meteorite rush of all time! When it is over, it will never happen again. Not only are large quantities of very affordable meteorites making their way into the marketplace, but many rare ones that most of us have not previously even heard of are becoming easily available. This is affecting the price of ALL meteorites, not only those from Africa. (Just one example: in the 1960’s rarely available hexahedrites were aggressively sought after when small pieces became quietly available at $ 5.00/g. Today, large and exquisite slabs of Frederickburg, an equally exceptional hexahedrite, recognized by Mike Farmer, is readily available around $2.00/g. One of the many great non-NWA bargains out there!
We’ll touch upon thin sections, their use and importance (get a bit into polarization and birefringence) and illustrate with many very nice color pictures.
I welcome suggestions regarding format, content and anything else that might be of use to this series. I see my role here as a gatherer of ‘basic ideas’ in order to create a “repository” of information for whomever it May serve. (I will remind readers that my background is in Astronomy, not geology, petrology or geochemistry. Should (and when) errors May occur, I will appreciate having them pointed out.)
My allotted space for this introduction is about used up, so I will close with a request to readers to let me know the direction in which you think this series May want to go. (I receive many questions every week, so I already have a number of ideas regarding what might be discussed.) Please send your comments and suggestions, as well as a list of those special topics you might wish to have mentioned. I am open to “guest authors” who May be interested in using this space to express an expertise in a favorite topic. This feature would be a welcomed and valuable asset. If you are such a person, please offer your services if you would like to tell us something about your special interest.
Department of Earth Sciences & Astronomy
Mt. San Antonio College
Walnut, CA 91789 (U.S.)