As someone pointed out to me, I can hardly advertise a show in Arkansas without also advertising the upcoming show in St. Louis. So here it is: it’s the weekend before the Arkansas show, easily accessible from Kansas City, and I am sure it will be fun.
MOZARKITE, MISSOURI’S STATE STONE by Roger K. Pabian
(Editor’s note: This article was written by Roger and printed in The Gemrock in 2002. It is written about a field trip taken by Roger and Bill and Betty White.)
On May 3, I took a trip to Kansas City and then on to Lincoln, Missouri, to examine the in place occurrence of Mozarkite, the Official State Gemstone of Missouri. As part of my ongoing study of cryptocrystalline and amorphous quartz family gemstones, I thought that the Mozarkite mine would be a worthwhile trip.
In Kansas City, I joined up with Bill and Betty White on Friday afternoon. Bill and I spent much of the afternoon at one of the major tool houses there and I purchased quite a few diamond tools and other tools that would be of use for stone and metal work. We also hit one of the retail salvage outlets, a store that carries distressed merchandise, as they often have many tools of considerable value for very low prices.
On Saturday morning about 7:00 A.M. we left Independence for the small town of Lincoln, Missouri. The town is famous for its annual rock swap in September. There we teamed up with Linville Harms, owner of the Mozarkite mine, and then went on to the mine. The attached photos of the Mozarkite and the Mozarkite mines help you get a better idea of what the site is like.
Mozarkite is not an accepted mineral name but is simply a trade name that was developed to promote the acceptance of the stone as Missouri’s official State Gem and to generate sales to both lapidary and tourists. The name has found acceptance in some circles but is not an acceptable mineral name in others.
Mozarkite has formed in place in marine sedimentary rocks of Ordovician age — it probably is most common in the Jefferson City Formation. The Jefferson City Formation is comprised mostly of dolomite with silty and cherty stringers running through it. There are very few fossils in dolomized rocks as the addition of magnesium to the calcium carbonate of the limestone usually results in complete re-crystallization of the rock and destruction of any fossils or sedimentary structures therein. We did observe a fragment of a brachiopod shell that escaped destruction. It appeared to be a flat-shelled, long-hinge lined form, probably a strophomenoid, but no other determination could be made of it. Much of the local lore about Mozarkite attributes it to igneous activity but there is no evidence for any in that area of Ordovician or younger rocks.
The Mozarkite appears to be of strictly marine sedimentary origin. Some of the nodules show evidence of an accumulation of siliceous gel or ooze on their outer surfaces.
There appears to be three different facies of Mozarkite. The gemmy kind is a dense, brittle form that shows no crystallinity at 10X magnification. A second kind is what the locals call “sugary” Mozarkite. Some of this is quite colorful and has interesting patterns and enjoys some gem use. The “sugary” kind, However, this does not polish nearly as well as the dense, brittle kind. Then, there are some nodules that appear to be very fine sandy textured.
The three facies or textures of Mozarkite suggest that sorting of particles may have been one of the key factors in the origin of the material. Sorting of particles simply means that as some energy form such as wind or flowing water moved a mixture of unconsolidated particles, the heaviest or largest particles are the first ones to drop out of suspension. You can observe this phenomenon on the gravel bars of a stream or in the bars along beaches, estuaries, or lagoons. The coarsest particles will be on the upstream end of the bar or nearer the bottom of the bar. It may well be that the gem Mozarkite is a quartz argillite, a sedimentary rock made up of quartz particles of clay size, that is, smaller than 1/256th of a millimeter. The gemmy facies could also be derived from silica of organic or volcanic origin. The “sugary” facies is made up of the particles larger than 1/16th but smaller than 1/4 mm.
The source for the silica that makes up Mozarkite is currently not known. It may have been from Precambrian granite rocks that are found to the south and east. Sponge spicules may have been the source of silica; I will not totally disregard them. However, I usually favored volcanic ash as the source of siliva for large bodies of chert or flint in marine sedimentary sequences. If there was any volcanic activity involved with Mozarkite, it was from volcanoes that were far away from the Mozarkite-bearing strata.
Mozarkite is a very interesting gem material that could shed a lot of light on the geologic events and processes that led to its formation. My comments above are only a few ideas about its occurrence. Like many other ideas on his stone, my hypotheses need more documentation before they can either be accepted or rejected. My hypotheses should probably read as follows: “Mozarkite is a quartz argillite of marine sedimentary origin that formed in situ in shallow seas of Ordovician age. The source of the quartz is shield rocks of Precambrian ages that lie to the southeast of the area from which it is not found.”
To prove that, several things need to be done. First, properly oriented (top and north) nodules need to be collected from in place in the mine pits. The nodules should not be examined in the field to avoid “high grading” the material. An outcrops map or diagram would need to be made that shows the places from which each nodule was taken. Similar sampling should be carried out from several different layers in several different parts of the mine. The facies of each nodule would need to be located on the map. Does one zone produce only sandy material whereas another produces only gemmy material? Or do these facies occur at random? Thin sections (30 microns) would have to be made. The nature of the particles (angular or rounded) and any cement between them would need to be noted. Is there a silica cement between the particles or does their angularity hold them together? Then other occurrences, both geographic and stratigraphic, of Mozarkite would have to be noted. The sedimentary structures in the Mozarkite and the host rock would also have to be observed and recorded.
By the time all of this is done, one has done enough work to earn a Master of Science Degree. As you see, there is no easy answer for Mozarkite. Perhaps, as a club, or group of clubs, we might think of funding a student to carry out the above kind of research.
Show-Me Rockhounds member Dan Snow has provided these geologic maps of Kansas City from 1917 which contain topographical, geological, and cross-sectional data. The maps show where to find several different types of rocks common to this area. They are also a great way to see how Jackson County has changed in the last 100 years. The maps are in PDF format and are very high resolution, so please zoom in!
Next weekend (June 10, 2017) we are going on a trip to the Missouri Mines Rock Swap in Park Hills, Missouri. We will look for drusy quartz and possibly Missouri banded agates. The swap itself goes from June 9-11 if you want to stay longer and is located at the Missouri Mines Historic Site near St. Joe State Park, 4000 MO-32, Park Hills, Missouri 63601. FREE admission to the show!
Directions: From Missouri 32, get off at Federal Mill Rd and look for the Missouri Mines Historic Site. Google Maps
The Spring 2017 Gem and Mineral Show was very successful. The parking lot was filled to capacity and we made over $3000 for the scholarship fund. I think it helped that it was so cold on Saturday, because people wanted to do something indoors. Here are some of the highlights.
Some rockhounds went on a field trip to Joplin, MO in September 2016. They looked for rocks and went to the Joplin Museum Complex, where they gave the museum a donation from the Friends of Mineralogy, which is a national non-profit group of people who love studying minerals. Many of our rockhounds are members of multiple clubs, including this one. The Friends of Mineralogy make donations such as this one because they are a 501(c)(3) organization and because the Joplin museum is really cool and deserves it.
When: 6:30-8:30 p.m. Friday, June 17 (21 and older)
Enjoy drinks and light bites while you view a fascinating collection of fossils and hear from renowned University of Kansas Paleontologist Dr. David Burnham about the unique and ferocious Dakotaraptor. Prepaid reservations of $30/person or $25/member required. You can make those reservations at https://www.powellgardens.org/dino-soiree or by calling 816-697-2600 x209.
Guests will get one drink ticket, which can be exchanged for wine, beer or a non-alcoholic beverage at the bar. Additional drinks will be available for purchase.
Come early if you would like to take a self-guided tour of Jurassic Garden: A Prehistoric Adventure! If you cannot make the paleontology lecture, there are some other events at the Jurassic Garden: Dining with the Dinos on June 24 (reservations for BBQ dinner with dinos) and Dino Night July 22 (reservations for Dino Night). The Jurassic Garden will be available until August 14, 2016.
If you came to our January meeting, you will know that we are now offering door prizes just like at IGAMS. All my spying on IGAMS meetings is proving to be very helpful! January’s door prize was part of Kansas City’s Composita layer. Composita is a genus of extinct brachiopods that were abundant during the Pennsylvanian era. Brachiopods are bottom-dwelling marine organisms that have two shells and a little fleshy “foot” called a pedicle. In a fossil brachiopod, you can see the hole where the pedicle sticks out of the shell, which is called the pedicle valve. In the upper part of the Winterset Limestone in Kansas City, there is a zone consisting almost entirely of Composita shells. See Chapter 11 of Dr. Gentile’s book for more information. Some of the shells in this specimen even had crystals inside. It was collected by David Reed somewhere in the Kansas City area, but he’s not telling exactly where.
Brachiopods have two shells, but they are not bivalves (an easy mistake to make). Bivalves are a class of mollusks, like clams, and do not have pedicles. Bivalves are symmetrical, and brachiopods are not. In fact, the bivalves may have caused the extinction of the brachiopods due to competition for food and living space.
Rocks and Fossils of the Central United States with Special Emphasis on the Greater Kansas City Area by Richard Gentile
Review by David Reed:
This book is great! It has beautiful pictures of the fossils that can be found in Kansas City and clear stratographic sections explaining the geology of the area. It also shows locations for picking up the fossils. Everything you might wish to know about Kansas City is in this book. Well worth the money and you can ONLY get it at UMKC (Amazon doesn’t have it). We purchased one when we visited the Sutton Museum.
On July 21, 1967, the mineral galena was adopted as the official mineral of Missouri. Galena is the major source of lead ore, and the recognition of this mineral by the state legislature was to emphasize Missouri’s status as the nation’s top producer of lead. Galena is dark gray in color and breaks into small cubes. Mining of galena has flourished in the Joplin-Granby area of southwest Missouri, and rich deposits have been located in such places as Crawford, Washington, Iron and Reynolds counties. (RSMo 10.047)
The specimen pictured is from the Southeast Missouri Mining District in Reynolds County, MO.