Magnesio-riebeckite - Franklin, NJ

Description

A very rich museum-quality example of magnesio-riebeckite. This mineral species was once known locally as "crocidolite," which is NOT a valid species name and merely an old-fashioned varietal name. Magnesio-riebeckite is a member of the complicated group called the Riebeckite Root Name Group > Sodium Amphibole Subgroup > (OH, F, Cl)-dominant Amphibole Group > Amphibole Supergroup. Magnesio-riebeckite is a sodium magnesium iron silicate hydroxide amphibole, and the type locality is in Bolivia. The color is a light blue with a dull luster. It looks as if it were blue chalk. The in situ occurrence of this species is little understood as there are very few examples of this species with additional mineral associations. It appears to be a very late stage of formation within the Franklin orebody, and this particular species is not known from Sterling Hill. There are abundant, coarse, semi-vitreous portions of blue calcite in the matrix, along with a few spots of oily, pale green sphalerite. This specimen was formerly in the Princeton University Collection. This is a museum-quality example that would grace any collection of Franklin and Sterling Hill mineral species.
Dimensions are
17.5x13.2x7.5cm - 7x5¼x3in.
Please note the centimeter cube and inch bar for scale.
Weight in grams and ounces:
1514.7g - 53.43oz.
From the
Franklin mine, Franklin, NJ.
The previous collection this specimen was in is
#114, Earl Verbeek.
#114 is the museum's Collection Sale number previously offered in the museum shop.
>>> We do
COMBINED SHIPPING
for multiple items. To
request
an invoice from us that combines shipping
ALWAYS
, click the
Add to cart
button on eBay to add items until you are done.
DO NOT PROCEED
to checkout; instead, click the
Request Total from Seller
button. <<<
=== There is an instructional video on how to request combined shipping is here
https://www.youtube.com/watch?v=FvDe7Fg7R4Q
===
All potential buyers need to be aware that being able to view fluorescent minerals requires an ultraviolet lamp. Most of the minerals from the Franklin and Sterling Hill zinc mining district fluoresce under
shortwave ultraviolet light
.
The shortwave wavelength is
254nm
or otherwise known as
UV C
. Always read the description carefully to determine if the main mineral of interest for a particular specimen will fluoresce.
ALL
fluorescent minerals depicted in our storefront are illuminated by two (2) 9 watt Triple short/mid/longwave AC Model 9SM-110 Way Too Cool LLC ultraviolet lamps, and the shortwave tubes and filters were replaced in late 2018.
There are several available brands and models of ultraviolet lights on eBay and other online sources. For further information on ultraviolet light and fluorescent minerals, copy and paste the following and go to >>>
geology.com/articles/fluorescent-minerals
.
>>>>
We Buy Collections
<<<<
DISCLAIMER: Every reasonable effort was made to identify the mineral species noted in each specimen accurately. The occasional label from previous collection(s) may misidentify some species, and the current title and description here reflect the latest mineral species identification. There may or may not be any fluorescent mineral species present in this specimen. A fluorescent photograph may not have been included for several reasons. Chief among these are; there may not be any fluorescence in this particular specimen. If there are fluorescent species, it is considered minor and not the specific species of note in this particular specimen. Another reason not including a fluorescent photograph is that some mineral species may be too weak to record even with modern photographic technology and photo-enhancement. If such fluorescent species were present in this specimen, it would be noted in the descriptive text.
A modest effort was made to depict a fluorescent specimen accurately as possible.
In some cases, overexposure should be expected in select photographs to compensate for a fluorescent specimen's weak response.
All buyers should exercise safe viewing practices regarding the use of ultraviolet light. Visual dark adaption is highly recommended in the optimal viewing of fluorescent minerals. Buyers should also be aware of what type of lighting to view the specimens under. This can result in perceived differences of color and contrast due to color and contrast shifting under various kinds of lights available.
All photographs were taken with a Nikon D5300 digital camera with a Nikon DX AF-S 18-55mm lens attached with a UV filter. Lighting was done with a pair of OSRAM 8.5 watt LED A19 5000K 800 lumens bulbs in brushed aluminum reflectors. The photographs were processed on a color-calibrated flat panel monitor. Do note the Imperial measurement conversion is the nearest equivalent to the listed metric measurement.
--- All photographs appearing on this listing or any other Franklin Mineral Museum listing are the property of the Franklin Mineral Museum. Photographs
can be used strictly for personal use onl
y
. Otherwise, the photographs posted here are protected by U.S. Copyright Laws. They are not to be downloaded or reproduced for public use or distribution in any way without the written permission of the Franklin Mineral Museum. ---