Description: If you are making multiple purchases, please read the note that follows the red text below! Soft white talc from the Acme Mine, Alexander Hills, California - teaching hand specimen Talc's hardness is 1 on the Mohs' scale, and its perfect cleavage in one direction (like mica except more loosely attached) allows tiny flakes of talc to easily slip past each other, giving it a smooth or greasy feel. Talc is usually white, slightly green, gray, brown or colorless. It has multiple industrial uses as an ingredient in paints, insecticides, rubber, paper, plastics, ceramics, roofing and baby powder. By far the greatest amount used in the U.S. is in the manufacture of paper. The Western Talc Mine - Acme mine was the second largest talc mining operation in the Death Valley region. The southern Death Valley area talc deposits are some of the best examples in the U.S. of talc formed by contact metamorphism. Mining began there around 1910. There are at least 43 talc mines and prospects in the region. This talc formed when a cherty dolomitic horizon at the bottom of the Crystal Spring Formation was intruded by gabbroic sills in the Mesoproterozoic, roughly one billion years ago. The sills were emplaced before the overlying limey sediments had consolidated and while they were saturated, perhaps by marine water from an overlying sea. Contact metamorphism produced the talc along the contact between the sill and the carbonate metasediments. Two gabbroic sills in the area gave U-Pb radiometric ages of 1087+ and 1069+3 million years. The Death Valley talc has been used mainly in the manufacture of ceramic wall tiles and as an extender in paints. This talc is soft and will not withstand student examination unless supervised. We recommend it as a display specimen. The pencil is 5 1/2" long, for scale. Select a specimen: When more than one specimen is shown, you can select a particular specimen by telling us what is in the photo with it - a black mechanical pencil, a silver and black 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 or Ground Advantage, whichever is cheaper, unless we can find a better rate. Rates vary 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!
Price: 10.45 USD
Location: Olancha, California
End Time: 2024-12-03T09:33:41.000Z
Shipping Cost: N/A USD
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Return shipping will be paid by: Seller
All returns accepted: Returns Accepted
Item must be returned within: 30 Days
Refund will be given as: Money Back
