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Mineral Collecting - Frequently Asked Questions
Minerals are the materials of which rocks are made. A common example is granite, which is composed of the minerals quartz, feldspar, and mica. Each type of mineral has a distinctive composition and certain chemical and physical properties. With practice you can learn to recognize many common minerals that occur in Maine rocks. There are places in this state (and many other parts of the world) where rare and colorful minerals can be found. In some cases they occur as nice crystals, which are especially appealing to collectors. Crystals may be suitably durable and flawless to fashion into gemstones. Mineral collecting is an outdoor hobby enjoyed by people of all ages and backgrounds. It provides a good opportunity to learn about earth science, both outdoors and at home.
Mineral collecting is one of the least expensive hobbies. Interesting minerals often can be found on the surface of the ground in places such beaches and construction sites, as long as access is permitted. Most collectors bring a pail or knapsack to carry their finds in areas where some hiking is required. The most useful tools are sturdy hammers for breaking rocks open, and a small shovel for digging through piles of broken rock on the waste piles of mines and quarries. Many other items are handy for collecting and staying comfortable during outdoor activity. Additional suggestions are available in the Collector's Guide to Maine Mineral Localities.
Dozens of old feldspar and mica mines are scattered across parts of Androscoggin, Sagadahoc, and especially the southern half of Oxford County. These mines are located in veins of very coarse-grained granite called "pegmatites". Collectors dig through the piles of waste rock from mining operations, looking for crystals of quartz, garnet, beryl, and tourmaline, along with traces of the rarer minerals sometimes found at these mines. Be sure to heed "No Trespassing" signs and ask permission where required. The Collector's Guide lists a number of popular collecting sites in Maine. While these sites are believed to be open, access conditions may change overnight, and we can make no guarantees that every listed site will be open.
Adventurous collectors will seek new mineral discoveries at construction sites and any other places where freshly exposed rock can be examined. A careful search of geologic and mineralogical literature may encourage you to prospect areas far back in the woods where few people have looked for specimens. As with mines and quarries, be sure to check on property ownership and obtain permission where required.
Mineral recognition takes some time and experience. One of the best ways to identify minerals is to study labeled examples in collections, or those offered for sale by dealers at shops and mineral shows. It is especially helpful to join a club, of which there are several in Maine, and attend their meetings and field trips. Club members are usually glad to assist the beginner. See the list of Maine mineral clubs on this web site.
Many books on rock and mineral identification can be found in bookstores or by purchasing through the internet. These publications will guide you through the identification process using simple observations of color, hardness, and other properties. The photos in most books show choice crystal specimens which may be far better than what we are likely to find ourselves! The same is true of minerals displayed in museums - they may be wonderful to look at, but not typical of what's available to the collector. Many minerals can also exhibit a wide variety of colors and shapes.
Yes - and many collectors rely on swapping and purchasing specimens to improve their collections (the so-called "silver pick" method of collecting). While there are lots of people who collect only the minerals they find themselves, it may take considerable work and luck to find choice specimens in the picked-over rock piles of old mines. For this reason, collectors often decide to broaden their horizons by swapping with other hobbyists or purchasing from a mineral dealer. Nice crystal specimens from all over the world are available at prices from less than a dollar to the equivalent of buying a house. It pays to shop around and browse the offerings of local "rock shops" and dealer web sites. Specimens, books, equipment, and much information about minerals are also available in magazines such as Rock & Gem or Rocks & Minerals.
Gemstones are varieties of certain minerals that have adequate color, hardness, and transparency to yield beautiful cut stones. The finished gems that you see in jewelry stores do not occur that way in nature. They usually have been fashioned by cutting and polishing the best parts of gem-quality crystals from around the world. Precious gems such as diamonds, rubies, and emeralds are not native to Maine, but some very good semi-precious gemstones have been found here. They include the gem varieties of quartz (colorless, rose, smoky, and amethyst), beryl (as blue aquamarine and pink morganite), and tourmaline (pink, green, blue, and multicolored). Deep red garnet crystals sometimes contain clear areas that are suitable for faceting, but usually yield only very small gems.
Tourmaline is the official State Mineral of Maine, and the most valuable and highly sought-after gem material that can be found here. Gem tourmaline has been mined in Maine since the 1820's, and the oldest location (Mt. Mica in Paris Hill) is still producing today. Tourmaline is actually a group of minerals having various colors and compositions. The black iron-rich schorl is most common in Maine. It may form sharp crystals but is not a suitable gem material. The species called "elbaite" is very colorful, but only a small percentage has the desired transparency for gem cutting. Many jewelry stores sell tourmaline from other parts of the world besides Maine, so you may want to get a written guarantee of the source if you want only authentic Maine tourmaline. See the Tourmaline Fact Sheet for more information on this mineral.
Small gold nuggets are panned from several streams in western and northern Maine. The West Branch of the Swift River in Byron is the most popular site. There are doubtless many other streams where traces of gold have been found, but the prospectors who find these hot spots are not likely to publicize them. The Maine Geological Survey's Gold Fact Sheet lists sources of further information on gold prospecting techniques.
Real gold has the rich yellow color of gold jewelry, and a gold nugget will flatten when struck by a hammer. Other minerals with a golden color, such as pyrite or chalcopyrite, are brittle and will crumble on impact. Many people mistake small biotite mica flakes for gold. Biotite is abundant in many rock formations in Maine, and it weathers to a bronzy golden color. However, this mica mineral is much lighter in weight than gold, and can be split or crumbled when prodded with a nail or knife blade. A good magnifying glass (hand lens) is very useful for close examination of suspected gold and minerals in general. A final note: academic and government institutions in Maine do not have assay labs or other mineral testing facilities available to the general public, because of the cost and time required to maintain and operate analytical equipment. Staff at colleges, the Maine Geological Survey, and Maine State Museum may be able to visually identify minerals if you call ahead and arrange a visit.
Last updated on April 10, 2012
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