Questions and phone orders: 10 AM - 10 PM Pacific (760) 920-6465
We will be out in the field, collecting, through January 24. Orders will ship on January 25 and 26.
1 left

sandstone - fine grained - teaching hand/display specimen of an unusual arkose

$ 7.50

This fine-grained sandstone is surprisingly an arkose, which means that a large percentage of the sand grains are feldspar. It is a bright and clean sandstone, not the coarse grained rusty arkose we visualize as typical. The flat cleavage surfaces of the feldspar grains are clearly visible under 20x magnification. Under a 10x hand lens, these sparkle when the specimens are tilted back and forth. This is a useful example of a fine-grained sandstone, and most students will see it as that. An advanced student of geology might pick it out as an arkose. It is Upper Miocene in age, from the Cajon Valley Formation, terrestrial in origin. The cement is silica, so there is no effervescence with a drop of hydrochloric acid. 

The sand grains in these specimens are larger than those of a silt and will feel and look like fine sand to a student. It would be instructive to compare this sandstone with one is larger grained, with one that is cemented with calcium carbonate, and with different colored sandstones, as sandstone has great variety and a student should not see only one example

Ships in a Regional Priority Mail box and can be combined in that box with other purchases. Please request an invoice to avoid overpaying shipping, by clicking the "combine shipping" button in the cart. Click >here< for shipping rates. Use back button to return to this page.

Select a specimen: You can select a specimen by telling us what is in the photo with it, a black and silver pen, a black mechanical pencil or one of those plus some number of coins, or you can let us make the selection. These are slightly thicker than hand specimens, too thick for a small flat rate box. Best if ordered with other specimens, which can share the same box.

Making multiple purchases? Click on the "combine shipping" button in the shopping cart. We'll send an invoice with combined shipping. A link in that invoice will bring you back to checkout, no hassle.