Everybody loves the beauty of natural rocks and minerals. However, not everybody knows the meaning of all the terms used in the industry. I?ve prepared this guide to help those people understand more about the item they are thinking of buying. Here are just a few of the common and their definitions:
High grade
High-grade material is exceptionally good. Also to high grade a mineral collection is to sort out the best specimens.
Mine Run
This is usually used to state that the material is sold as it comes out of the mine. The good and bad mixed, it has not been sorted or high graded.
Psuedomorph
When one mineral completely replaces another, but retains the same outer shape of the replaced mineral.
Drusy
Drusy is a layer of crystals that formed within a cavity of rock. Amethyst crystals are often found in a drusy. The inner cavity of agate geodes is often lined with drusy of tiny sparkling quartz crystals. These crystals reflect (or appear to be) the color of the rock underneath.
Vug
This is a natural hole or hollow area in rock. Also called a pocket or cavity.
Botryoidal
This literally means ?cluster of grapes? and is used to describe a rock that has a bumpy or grape like surface.
Inclusion
Buying Amethyst on Ebay. Sellers Point of view.
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This guide is for those who are looking to get the most value for your money. I will focus on amethyst from South america because that is what I sell on ebay. I've sold it on ebay for over 6 years.
First thing you need to know about amethyst:
Amethyst can be found all over the world. It is sold by color. The lighter the amethyst the more inexpensive it is. The darker it is the more expensive it is. The two most common mining districts are found in Brazil and Uruguay. The biggest difference between the two is that amethyst from Uruguay has a much deeper darker purple color and normally brings a lot more money per specimen. Am I saying Uruguay amethyst is the best? NO, certainly not. Only you will be able to make those opinions.
Buying on ebay: The biggest tip I can give you is buy more than one item and save on shipping from same vendor. Ask about Flat rate box shipping. That's how I sell most of my amethyst specimens. Don't spend 6.99x5 times on shipping. that's crazy. Ask for discounts. Ask Ask Ask, if you don't ask you'll never know. Ask about discounts on dollars spent, lbs bought, or if they have free shipping if you hit a certain dollar amount.
Types of Amethyst.
I will list some of the most common types of specimens available on ebay. This is not a complete list but will help you whe making selections for what you want to buy. Or what you may want to add as an additional specimen to your collection.&...
CHALCEDONY, JASPER, AGATE
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Chalcedony (kal SED' nee) is any form of microcrystalline quartz , where the crystals are too small to be seen without high magnification. However, in the rock world, only the translucent or transparent, single color types are sold as "chalcedony". (The exception would be Carnelian, a blood red variety.) Other colors are white, blue, purple, pink, yellow, orange or red. The various types differ in color due to metallic impurities, such as iron, nickel, copper, and titanium present during crystallization.
Chalcedony forms in rounded crusts, rinds or stalactites in volcanic and sedimentary rocks. The name probably comes from Chalcedon or Calchedon, an ancient port city on the Sea of Marmara in modern-day Turkey. They usually have a waxy luster and a hardness of 7. Chalcedonies are tough gems, good for all jewelry applications and require no special care in wearing or cleaning.
Some varieties of Chalcedony and their localities are:
Chrysoprase ? gets its green color from nickel. Most chrysoprase sold today comes from Australia.
Chrysocolla - Marketed as "Gem Silica" this relatively rare, blue to blue-green, opaque to near transparent material is the most expensive type of chalcedony. Found almost exclusively in Arizona its color is due to copper.
Blue Chalcedony -The various blues are generally named by their localities. The colors vary greatly from gray to lavender. They also vary in the amount of translucency.
Bustamite - An extremely rare pink variety from South Africa. It is found in the manganese mines and the color can vary from pale pink, to du...
Keokuk Geodes - Discover the Mystery
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Geodes have been a mystery though out the ages. The word "geode" is derived from a Latin word meaning "earthlike?, a round spherical shape. Geodes are formed with an inward growth of crystals on the walls of the geodes and are not wholly filled. Geodes that are completely filled are referred to as ?nodules? and are no longer considered a geode. Hollow geodes are lighter than ones that are completely filled. The most sought after geodes are hollow ones and sometimes they will even rattle with loose crystals inside. Come and discover the hidden treasures of the Keokuk Geodes!
325-360 million years ago, the Mississippian time period, mud was deposited into shallow seas in Iowa, Illinois, and Missouri areas. The mud was calcium carbonate and clay that turned into shale and limestone. This is host rock that geodes are found in. It is weaker than the outer shell of the geode. Geodes are more resistant to weathering than the host rock that surrounds them. This means geodes will eventually ?fall out? of the host rock by natural weathering.
Recent research has established three general points on how geodes are formed:
1) Geode precursors were concretions (nodules formed by outward growth around some nucleus) which grew within soft, unlithified sediment.
2) The outer shells of these concretions were replaced subsequently by chalcedony.
3) The interiors of the concretions were dissolved, leaving a hollow space into which quartz crystals could grow. The composition of the original concretions is unclear, though geologists propose they were either limestone or anhydrite, a fairly soluble calcium sulfate mineral related ...
Amethyst Cathedrals and the Avid Collector
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We've traveled to Tucson in the past, which transforms every February into the international (truly global) marketplace of rocks & minerals & fossils & gemstones & beads, not as a small business on ebay as we are now, but as enthusiastic new rock collectors accompanied by a friendly company of older (and experienced) rockhounds! As Joe's Rock Shop's Guide noted earlier, the cement base of a cathedral adds to its weight, so consider its size in proportion to the crystal when valuing an amethyst cathedral. There shouldn't be a cement base for an amethyst cluster or piece, but a nice wood or acrylic base is a plus. Note that the paint job on the outside is required for resale in the US, because (from what I've read) it helps seal in the metals naturally found in these crystals (note to parents: definitely not a chew toy). But here's my point, as an avid collector, professional, or first-time buyer, you can find good value! The deeper the purple color, the higher the price will go, but if the color is light, don't discount it. Consider the form and completeness of the crystals, whether you like a look that 's more druzy in appearance or mathematically cubic, the cathedral's overall shape, but most importantly, its appeal to your uniquely personal tastes ... Remember, you can enjoy a piece of earth history at a good value!
Maria, Wm's mom
www.stores.ebay.com/Treasure-for-...
Rocks & Mineral Identification-A Rockhounder's Guide
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This is not for the serious collector who spends big bucks on specimens, nor someone who wants an appraisal on their collection. This is for the person who loves rocks, buys them because they look pretty, or goes out in the hills to treasure hunt. Most of us remember collecting rocks as kids. We didn't care if they were valuable. We just cared that they were pretty and we enjoyed them. Mine I kept in a flowerpot in my window, and then later in a garden in my front yard.
I'm writing this guide to help you understand a little better what some of these minerals may be or how to find more of them.
First off, what is a mineral? Or a rock? Wikipedia states "A mineral is a naturally occurring substance formed through geological processes that has a characteristic chemical composition, a highly ordered atomic structure and specific physical properties. A rock, by comparison, is an aggregate of minerals and need not have a specific chemical composition. Minerals range in composition from pure elements and simple salts to a very complex silicates with thousands of known forms. To be classified as a "true" mineral, a substance must be a solid and have a crystalline structure. It must also be a naturally occuring, homogeneous substance with a defined chemical composition."
Rocks can be one mineral if they are massive, but are more commonly several minerals cemented together. They can also be organic (amber, fossils...), or like obsidian; a natural glass that varies in chemical composition. Or even a meteorite!
Currently there are more than 4000 known minerals, according to the International Mineralogical Association, who approves and names any new minerals found. Of these, about 150 are considered common, 50 are f...
Fluorescent Minerals
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I am not a specialist in fluorescent minerals. But in my years as a rock dealer I have seen many fantastic dark room displays of rocks glowing in all colors of the rainbow! Many times when the UV light (Ultaviolet) is switched off and the regular lights switched on, the minerals are very unexciting and not colorful at all.
I do have a UV light and I like to check out some minerals now and then (as well as the scorpionsaround here!).
Often I am asked if one of the minerals I sell on ebay will fluoresce. The truth is-I don't usually know. But I thought it would be fun to privide some basic information for the beginner collector.
Fluorescence is caused by the incorporation of small metal impurities in the mineral. These impurities often affect the color of the mineral. Copper can make a mineral green or blue, magnese can make them purple or pink, etc. Some of the trace minerals that fluoresce are chromium, maganese, cobalt, nickel, tungsten, etc. Because each mineral may contain a variety of these metals, not all minerals that are the same, will fluoresce the same. Fluoresce can help indentify a mineral, but is actually more reliable in determining a origin as many deposits have very distinct fluorescence. If iron is is present in any amount-it will prevent fluorescence!
The word "fluorescence" comes from the mineral fluorite, which was the mineral on which this light phenomenon was first discovered. Of course, strangely enough, only a little of fluorite responds to UV light! Minerals are displayed under a UV light with both long waves and short waves, as some will only fluoresce under one type of wave. The strength of the glow and the colors vary greatly. Sometimes the glow will persist even after the UV light has been turned of...
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