Museum: Fluorite and associated minerals Section 2  

Go to Fluorite Museum Section 1
                                                                              
Go to Fluorite Museum Section 3

                                                                                  
 Go to Fluorite Museum Section 4:

             Spectacular fluorite stalactite!

Go to Calcite Museum Section 1
                                                                             
 Go to Calcite Museum Section 2

 


One BIG fin of fluorite, attachment  was on the left, above, showing the internal yellow fluorite

Flip side in the sun

Sunlight really brings out the color of the purple fluorite!


One big flat calcite sits on the right front side


Bitumen inclusions in a number of the crystals appear to have floated to the top corners of the crystals


Back view, covered with calcite and benstonite


Here the yellow fluorite shows some etching prior to deposition of the purple layer


Here the fluorite and some of the calcite overgrowth is covered with another mineral that forms little balls and coatingsof tiny flattened rhombohedrons

Plate of Yellow Fluorite with Purple Fluorite and Calcite

About six specimens in one, so there are lots of pictures of this one!

This plate is solid yellow flourite, with a partial overgrowth of purple fluorite creating a hoppering effect. The entire back and parts of the front are covered with small calcite crystals. This was a "fin" projecting off matrix, with the only attachment being on the left end.

Specimen Size: 12.5 X 32 X ~4 cm 

Ex- Rocky Quinn collection. At the time I bought this I knew only that this was collected from southern Illinois, reportedly in the 1935-1945 time frame. 

Ross Lillie (Northstar Minerals) was able to identify the probable origin as the Minerva #1 Mine, Bethel Level, Cave-in-Rock, Illinois. The mine was operated by the Minerva Oil Company. 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

In this picture you can see small, gemmy clear calcite partly covering the fluorite. One the far right a tan mineral coats the fluorite and in some places coats the calcite.
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

Kevin Conroy (KC Minerals) and Ross think the tan material is probably the rare carbonate benstonite (barium strontium calcium manganese magnesium carbonate!!), formula:
(Ba,Sr)6(Ca,Mn)6Mg(CO3)13 The material is definitely a carbonate, soft, reactive to very strong but not weak HCL acid as is calcite and has the flattened rhombs typical of benstonite. Ross notes benstonite didn't usually grow over flourite, but that this would just be less common. The crystals are identical to a large specimen of benstonite on calcite crystals on Rob Lavinsky's site in his Tucson 2007 update (see http://www.irocks.com/0207e.html if it is still posted).

 

 


 
 


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Elmwood, Tennessee fluorite, although with the strong zoning (look at the last picture) and color it could be mistaken for Illinois. This is the prettiest, most colorful  "Elmwood corner" I've ever seen. Glassy surface, clear inside the crystal. The window reveals a dark purple zoning, unusually pronounced for Elmwood. The crystal appears to be a "floater" with no obvious point of attachment, except at the back of the shining, silvery sphalerite. Chalcopyrites are embedded in the surface of the fluorite and on the sphalerite. Crystal form is unusual, too, in that it is rectangular, with one crystal face much longer than the those on the end facing the camera. The end is 5.5 X 4.2 cm, the length is 9 cm. Gemmy clear, no internal fractures. In the top two pictures you can see a strange "butterfly" inside. It's 3-4 cm inside the crystal.

Click on picture to enlarge
Fluorite, octohedron
Yaoganxian mine, Chen Zhou, Hunan, China

5 cm on crystal edges, very clear internally
 

Fluorite, octohedron
Yaoganxian mine, Chen Zhou, Hunan, China

The big brother of the one above, this specimen is 8 cm on a side!

I photographed it in my cabinet so you can see the back and hence see its shape better. The color, at least on my monitor, is quite accurate. It's a stunning deep green, very clear internally.

Colorless Fluorite

Naica, Mexico

The terminations are about 1 cm across and are part of a 6 X 8 cm specimen. 

I thank Peter Seroka for the following commentary on this exquisite crystal specimen:

"It is extremely difficult to determine the exact crystal structure of the Naica fluorite you sent to me. It's obviously a complex (if not complicated!) combination of a hexaedron with a hex`octaedron (thats for sure); however, as not few of the well known modified cubes from Naica have rounded faces 
(vicinal faces, which are difficult to 
photograph). I determine this to be a basic 48-face crystal combined with either rhomb dodecaedrons or icosi-tetraedrons. Its known that there are xtls from Naica 
with 72 faces."

The modified hexoctahedrons themselves sit on the ends of rough-faced larger incomplete octohedrons.


 

Grape Fluorite Octahedron on drusy quartz

The main crystal is 4 cm on a face.

Naica, Mexico

The faces of the octahedron are covered with perfect, gemmy, cube- octahedral, colorless fluorite. 

MORE FLUORITE!

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