Description: If making more than one purchase please read the instructions following the red text below! Teaching student specimens of a very pure slightly lithified white pumicite volcanic ash - unit of 5 specimens This pumicite tuff was mined for years in Last Chance Canyon in Kern County, California as the scouring agent in Old Dutch Cleanser. It is a pure volcanic ash with no included clasts, is not very dense, and will rub off on student's fingers. It looks just like a block of solidified scouring powder. It is similar to diatomaceous earth in appearance, though more dense than the diatomite. In 1905, Cudahy Packing Company was the first company to market scouring powder, originally sourced from a mine in Kansas. They began operations at the Last Chance Canyon mine in 1923. Twelve men were employed to produce 100 tons of pumicite per week. Ore initially was lowered 475 feet down a rail tramway to loading bins in Last Chance Canyon. From there it was trucked seven miles south to a Southern Pacific siding at Saltdale, where it was loaded on rail cars for delivery to Los Angeles. The mine produced 120,000 tons of pumicite before it was closed in 1947. That's a lot of cleanser. Many tuffs contain angular clasts (from the Greek klastos = broken) - fragments of other rocks welded in. As the ash was being blasted out of the vent, fragments of the surrounding rocks were being torn loose and blasted out with it. Angular clasts make a tuff easy to separate from a rhyolite, a lava with the same composition as tuff or granite. The rhyolite is entirely crystalline, though the crystals are often difficult to see without a 10x lens. In this case, an ash has to be identified by its gritty feel and not by included angular clasts. Students should see a variety of tuffs. Tuffs are extremely variable, though most are relatively light in color and relatively light in weight. They should be able to tell you where the included angular clasts came from, and should use the presence of clasts to separate a tuff from a rhyolite. We really don't like the tiny finger nail-sized specimens offered to students, as we feel these are too small to see rock textures and too small for examining the identifying characteristics of a mineral. We want the "Oh, Wow!" effect when students see the set of specimens they are going to work with. We collect these specimens so that five specimens, or possibly six, will fit in a small flat rate box, and we keep the price low, as we know these will be used in a classroom. For teachers we count like a baker and a dozen is more than 12, since you will always need a few spares. If you are a teacher, let us know. You are buying a unit of five student specimens. The photo is representative of what we ship. 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: Ships in a small Priority Mail flat rate box unless combined with other purchases. We always combine shipping to get your purchase to you at the lowest cost. We do not charge for handling. We refund any overpayments on shipping beyond our actual cost. A second unit moves the shipment into a larger box. We can generally ship 4 to 5 student units or a number of hand specimens in that box with no further increase in postage. 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: 4.6 USD
Location: Olancha, California
End Time: 2024-12-11T10:31:32.000Z
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
Modified Item: No
