Thursday, December 30, 2010

Minerals and Cutting Rough

About mid-January, we will be attending a major trade-show.  We expect to expand our offerings of minerals, Lapidary cutting-rough, and possibly even antiques.

These shows are largely unpredictable.  That is, one never knows what dealers, materials, or even countries will be represented. Therefore, we thought it might be smart to ask what 'things' you would like us to watch-for.  If you respond, it will not be treated as an "order", so you are under no obligation to buy anything you suggest.  We would just like to know what our clients and customers desire.  Then, if we are able to locate a good value, we'll offer it for sale through our store.

If you have a particular item in-mind that you would like for us to locate, please contact us through our website.  Please be sure to include your email address, as the software does not capture any information about you that you do not explicitly enter.

We look forward to your input!

Monday, December 13, 2010

Mammoth Fossils

Mammoths are some of the more famous members of the Order Proboscidea.  The Order Proboscidea includes elephants, mastodons, gompotheres, and other less-well-known animals with a pronounced 'proboscis'.   Mammoths flourished across much of of the northern hemisphere starting about 150,000 years ago, and ending about 10,000 years ago.  The Woolly Mammoth (Mammothus Primigenius) is arguably among the best represented of extinct animals on earth, due to their preservation in permafrost in the arctic.

The Latin root of the word "fossil" literally translates "having been dug up".  And fossils may be completely mineralized (like the wood found in the petrified forest in Arizona), or there may be little or no mineralization.  Heavily mineralized mammoth fossils are fairly rare, and usually limited to very old specimens.

The very best mammoth fossils frequently have almost no mineralization.  In the permafrost of Siberia and Alaska, very well preserved teeth and tusks are found which have not changed much since the animal died.  This 'fossil ivory' is highly sought for carving or other artistic use.  Similarly, the bones preserved in ice have very little mineralization, and require little special treatment to assure their continued enjoyment.  Unfortunately, access to these frozen beauties has become limited by legislation in their respective countries.

Another source of mammoth fossils are the relatively shallow seas which were dry, or covered by ice, during the ice-ages.  Modern fishing 'trawlers' drag the bottom of these seas in search of bottom-dwelling fish.  From time-to-time, their nets catch bones and teeth which have been submerged since the last ice age.  The fossils generally have a significant degree of mineralization...especially salt.   Special techniques are required to draw as much of the salt out of these fossils as possible.  And, these fossils tend to be somewhat fragile and ill-suited for carving or cutting.

Some mammoth fossils are found in fresh water, especially in Florida.  These fossils tend to be well preserved and somewhat mineralized.  Suitability for carving/cutting varies widely.  And, it would be highly recommended that each specimen be closely examined for any use other than display.

Mammoth fossils are also found in terrestrial locations.  The Mammoth Site of Hot Springs, South Dakota is well worth the trip and admission fee (although none of these fossils are for sale).  Mammoth fossils of terrestrial sites tend to be fragile, mineralization may range from minimal to substantial.  One would have to carefully examine each fossil for use other than display specimens.

Among the more common mammoth fossils are their teeth.  Mammoths (and modern elephants) grow six sets of molars in a typical life-span.  A "spit" tooth is a molar that has been shed in the normal process of an old tooth being worn-out and replaced by a new molar.  Curiously, the molars are constructed of alternating layers of enamel and dentin.  The dentin, being softer, wears more rapidly than the enamel, resulting in a constantly effective grinding surface (vs. a tooth that would have worn 'smooth' if all the same hardness).

The information above is the result of research, conversations, and observations.  And, reflects my opinions and experience.  We hope you will find it helpful.  But please, use this as only a starting-point for your research.