About Yellowstone Jewelry









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My name is Mark Ralston. I’m a registered Professional Geologist in Central Pennsylvania.  I've worked in earth sciences for about 30 years, including groundwater resource management, public water supply  development, and economic geology (mining).

In our free time, my wife, Linda, and I travel as often as we can to rockhound at various places throughout the US and Canada. We especially like Arkansas (crystal localities near Hot Springs and Jessieville), Nova Scotia (Bay of Fundy agates and amethyst), Maine (Oxford County pegmatites), Southeast Oregon (Owyhee Mountains area, Succor Creek, Cripple Creek, Graveyard Point, etc.), Idaho (Muldoon, Arco, Pearl, etc.), and, of course, Montana (Yellowstone River basin). We're also fortunate to live in an area where a beautiful oolitic chert can be found.  On the "Links" page I've listed some of the helpful people, rock shops, and other resources that we've encountered while collecting, for those of you who like to rock-hound.

The name, Yellowstone Jewelry, is taken from the source locality for my favorite stone (Montana agate) - the Yellowstone River basin from near Emigrant, MT to the North Dakota border. None of the stone on this website was taken from Yellowstone Park, since collecting is not allowed in the Park.

Geologic Information                      top of page

As a geologist, I’m fascinated by the geologic conditions that produce these beautiful stones. I will be posting some earth science information on the collecting localities for those of you who are interested in this sort of thing, as well as geologic and lapidary information on US gemstones.

Lapidary Information                      top of page

Translucent stones are cut in order to take advantage of light passing through the stone.  Some of the dense, mossy stones are cut thinner than some of the opaque stones for this reason.

I like to include some "tactile interest" in my cabochons, so many of the stones are cut from heel pieces, are irregular in thickness, may have a deep-domed back surface, and/or may have a non-traditionally shaped top surface.  Please check the scale bars on the photographs....  some of the cabochons are tiny, and many are fairly large.

All cabochons are finished on both sides.  Backs are generally finished with a very slight curvature, not flat.  Some cabs are cut with a deep back (crown up to about 3 mm - this gives the stone a nice feel), and are identified as such.  Edges are finished smooth (not sharp), with a very small (on the order of 0.2 mm radius) bevel.  This makes the stones less likely to chip when setting in bezel.

All dimensions are approximate, and all cabochons are cut free-form (i.e., not calibrated to fit a sized setting or bezel).  I try to cut the free-forms so as to highlight  any visually-interesting features in the stones, especially the Montana agates.  By request, many of the stones are visually symmetrical, but are not cut from templates.  Please let me know if you have any requests.

Jewelry Information

All of the jewelry on this website is in Centre Hall, Pennsylvania from free-form cabochons using sterling silver.   Silver mounting is done with a minimum of bezel and silver stock in order not to detract from the natural beauty of the stones.  Jewelry is generally made from small gage stepped-bezel, and is not backed with silver plate in order to allow light to pass through translucent stones, or to enhance tactile interest.

Bracelets are sized to fit the "average" wrist, and can be adjusted (adjustment instructions are included with bracelets).

Policies                     top of page

I price items on this website based on the following criteria:

  • How much time did it take to prepare or finish the stone ?

  • Quality of the stone’s finish (some visually-appealing stones are slightly porous and may not take a “glassy” finish).

  • How much time did it take to set the stone in silver ?

  • How much silver was used for jewelry items ?

  • Is the stone rare or unique ?  

I really care about the quality of the items that I sell, so I unconditionally guarantee your satisfaction with any purchase that you make on this website. If you don’t like something that you buy, please e-mail me, send the item back within one month, and I will refund the item’s price.

All images and content are copyrighted.  Please feel free to use any images, just cite the source.

Images                       top of page

Photographs are taken using a home-made light tent and about 600 to 800 watts of Sylvania Daylight® or GE Reveal® incandescent bulb illumination. Most items are photographed on a scaled, glass plate above a fabric background in order to allow transmitted light to shine through translucent stones. For pale, translucent stones like plume agate I photograph against a black fabric background.

I use a Nikon CoolPix L1 digital camera, with the camera set for incandescent lighting.  I check all images to make sure that the color and detail is as true as possible (within the constraints of making the images small enough to make the pages load for those of us with dial-up internet service).


Thanks again for visiting. I welcome any comments that you may have on this new website ! !