Description: If making multiple purchases, please follow the instructions after the red text below. Student specimens of lacustrine diatomite (diatomaceous earth) - Unit of 5 specimens Diatomite or diatomaceous earth is a sedimentary rock composed of the siliceous cage-like shells of diatoms, single-celled algae that live in the shallow water of lakes and the sea. As they die there is a constant rain of their shells onto the seabed and lake bottoms, where they accumulate to form chalk-like diatomite. The shells of diatoms are made of opal, so unlike calcareous chalk, diatomite will not effervesce with a drop of hydrochloric acid. Diatoms extract the silica of their shells from the water they live in. It takes special conditions to form a deposit of pure diatomite - active volcanism makes silica available, while very cold water inhibits the growth of foraminifera, the plankton with shells composed of calcium carbonate. Diatomite forms in high elevation lakes and in polar seas, and is found where similar conditions existed in the past. This lacustrine diatomite is from Mineral County, Nevada, from beds formed in a Pliocene-Miocene lake. Diatomite has industrial uses in filtration, in insulation and cat litter, as a filler in rubber, paint, cosmetics and plastics, as a mechanical insecticide and as a stabilizer in dynamite. It is also used as a polishing agent in toothpaste and as a component of some cement blends. 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 "view cart" and then click on “request combined shipping” at upper right in the Shopping Cart window. Do not proceed to checkout. We will send an eBay invoice with the correct combined shipping. 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 usually 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: 4.6 USD
Location: Olancha, California
End Time: 2024-08-19T01:45:49.000Z
Shipping Cost: N/A USD
Product Images
Item Specifics
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
