marble - large grained gray - large display specimen from the Lost Burro Fm.

Description

If making multiple purchases, please read the note following the
red text
below!
Marble - large grained gray marble from the Argus Range, California - large display specimen
This marble has very large crystals and is a unit of the Devonian Lost Burro Formation. It is associated with cyclically bedded and vertically tilted  limestone, field photos. It was quarried at the Valley Mine in Knight Canyon on the east slope of the Argus Range in the Panamint Valley, Inyo County, California, apparently along with dolomite for roofing or landscaping. The mine, operated by Metalline Industries of Grass Valley, California, has long been inactive. In the 1950s and '60s, gently-sloped ranch house roofs in Southern California
were often covered with loose crushed white dolomite gravel.
Marble and dolomite can look similar. Marble is calcium carbonate, derived by metamorphism from limestone. When further metamorphism adds magnesium, the result is calcium-magnesium carbonate, dolomite.
In the field and in the lab these two metamorphic rocks can be identified by their differing reactions to dilute hydrochloric acid. Marble strongly effervesces. Dolomite effervesces weakly or not at all, and strongly only when powdered by a few taps of the geologist's hammer. The difference will be obvious to students in the lab.
It would be instructive to compare this marble with a large-crystal dolomite. It can also look, at first glance, like a granitic rock missing the dark minerals. The granitics will not effervesce and they are much harder.
The pencil is 5 1/2" long, for scale.
Select a specimen:
If more than one specimen is shown, you can select a particular specimen by telling us what is in front of it - a black mechanical pencil, a silver and black pen, a silver and blue pen, or one of those plus some number of coins, or you can let us make the selection.
Making multiple purchases?
Just add items to your cart. When finished shopping, click on
“request total”
at upper right in the Shopping Cart window.
Do not proceed to checkout.
We will send an eBay invoice with the correct combined shipping.
The combined shipping will often be less than eBay shows. Please wait for that invoice before paying.
There is no obligation to purchase. You can decide after seeing what shipping will cost.
Shipping:
Priority Mail, which varies by weight and zip code. We can ship for less than eBay will charge, and will refund the overpayment as soon as the box is packed.
International customers:
We sell and ship internationally. If eBay’s page does not let you enter your country name to determine the shipping cost for something you are interested in, please contact us.  We can tell you what the shipping would cost and how to make the purchase. You can then decide if you wish to complete the transaction. Use the
Contact Seller
link in the Seller Information box on the right side of this page.
Pay securely with your debit or credit card through PayPal! You do not need a Pay Pal account to do this. Yes, we do combine shipping!