Description: If making more than one purchase, please read the note following the red text below! Teaching student specimens of gray perlite. Big Pine volcanic field, Inyo County, California - Unit of 5 specimens Perlite is a hydrated form of obsidian. When a mass of obsidian picks up water, it devitrifies and becomes amorphous perlite. The unhydrated core of the obsidian mass may weather out as an obsidian spherule called an Apache Tear. Perlite is mined, partly dried in a rotary kiln and screened to various sizes depending on its final application. To make the white perlite "rice krispies" found in garden supplies and nurseries, the partly dried perlite is heated to 1,600˚F. The internal water flashes to steam and the perlite pops, just like popcorn, and changes from gray to white. Perlite ore ranges from gray to black, with the black looking just like weathered obsidian, which it is. We stock the partly dried and screened perlite in the "before popping" stage as well as the final product. Inquire, as we have not listed these in the eBay store, though we plan to do so this month (February 2018). The series, from ore partly dried to final product makes a useful teaching set. These forms are available in 2 ounce jars and in 250 ml display bottles. 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: 2024-10-11T06:52:17.000Z
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:
