Description: If making multiple purchases, please follow the instructions after the red text below. Tuff with pumice clasts (fragments) - a classic ignimbrite or pumice-dominated pyroclastic depositThis particular volcanic igneous rock, the Bishop tuff, is composed of volcanic ash and fragments of pumice that were ejected from vents near Mammoth, California 700,000 years ago. It is a classic ignimbrite. Because the ash was very hot when it fell to earth, the ash and pumice fragments were welded together. The Bishop tuff is variable. These specimens were collected in one area where it contains darker pumice clasts (from klastos, Greek = broken in pieces).This is a self-teaching tuff. It looks ashy and is gritty to the touch. Students will get the picture. The pumice fragments are a light purple and the ashy matrix has a slight purplish cast. Tuff and rhyolite often look similar, since they have a similar silica rich composition and are both generally light in color. The angular clasts in a tuff separate it from a rhyolite.Tuffs are light colored, usually shades of buff or gray, and since they are silica rich, they are not dense. These specimens are fairly light for their size, reinforcing the volcanic ash origin.If you are a science or earth science teacher purchasing this as a teaching specimen for your class, this should be compared with other silica rich volcanic igneous rocks, tuff breccia, pumice (which is so full of entrapped gases that it floats in water) and rhyolite (extruded as lava) and with silica rich plutonic igneous granitic rocks. A tuff breccia will have larger fragments (clasts) of various igneous rocks than does this tuff. You are buying a unit of five student specimens. The photo is representative of what we ship. 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 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. ___________________________________________________________________ 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: By first class mail unless combined with other purchases. 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: 2024-05-07T03:41:22.000Z
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
Return policy details:
