Mini Me Geology Blog » sedimentary rock

What Would You Do With A Limestone Rock?

tracyb — Sun, 23 Oct 2011 14:41:46 +0000

Limestone is another very popular rock here at Mini Me Geology. We have several different varieties of limestone for your projects and collections such as fine-grained, oolitic, coquina and fossiliferous. Limestone also has many uses in your home and garden. Do you know what they are? Read more…

Do You Have a Sandstone or a Quartzite?

tracyb — Fri, 21 Oct 2011 14:31:20 +0000

Quartzites are metamorphic rocks that were once quartz sandstones. The quartz sandstones change to quartzite from high heat and pressure deep inside the Earth. Sometimes quartzite rocks have the same, bedded look as the original sandstone, making the two hard to tell apart. Learn more about a fun test for these rocks here.

What Would You Do With A Sandstone Rock?

tracyb — Wed, 19 Oct 2011 19:31:08 +0000

Sandstone is one of the most popular rocks here at Mini Me Geology. We have several different colors of sandstone for your projects and collections. Sandstone also has many uses in your home and garden. Do you know what they are? Read more…

Do you know Sandstone?

tracyb — Thu, 03 Feb 2011 15:46:22 +0000

Sandstone forms from beach sand-sized quartz grains that are glued together with quartz or calcite or compressed until they harden into a rock. Sandstone has a medium-grained texture and is often associated with water and oil storage because it has open spaces between the quartz grains.

Visit Mini Me Geology where you can find sandstone as an individual sample as well as a part of our My Rockin Collection Deluxe Sedimentary Rock Kit, our Junior Sedimentary Rock kit, and in our Sedimentary Sleuthing Rock Detectives kit.

Conglomerate Sedimentary Rock Q&A

tracyb — Thu, 03 Dec 2009 19:54:18 +0000

Here is another great question we received through our Ask-a-Geologist email.

Question: What grains are in conglomerate rocks?

Answer: Conglomerate rocks are made up of many different types of grains from sand to various types of rocks.

Learn more about conglomerate with our individual samples, My Rockin Collection Sedimentary Rock kit or our Sedimentary Sleuthing Rock Detectives kit.

Our Most Popular Ask-a-Geologist Question…..EVER!

tracyb — Mon, 22 Jun 2009 18:27:47 +0000

This has to be the most-asked question we receive here at Mini Me Geology. There must be a middle school or high school text book or worksheet out there that is used by many schools in the country. I think the question is worded a little funny, but here is the question and answer. For all of you teachers out there, take a look at this question….I think the weird wording is throwing the students off because I have been asked this question (worded exactly the same) dozens of times!

Question: What are the hollow ball-like objects, such as quartz, which are found in sedimentary rocks?

Answer: By “hollow ball-like objects” I believe you are thinking of geodes. Geodes are round in shape and hollow in the center. Geodes are usually filled with crystals such as quartz and amethyst. This photo shows several unopened geodes and some that have been cracked open with a rock hammer. The open geodes show the layers of quartz on the inside. Geodes form when an opening (hole) is present in a sedimentary or sometimes igneous rock. Silica-rich waters fill the opening and begin depositing agate and quartz crystals into the opening.

To purchase your own geodes, visit the Unique Rocks & Minerals section at www.MiniMeGeology.com. You will receive a set of 4 large (2″+) geodes that you can crack yourself. Full instructions for both cracking the geodes and doing it safely are provided.

Arkose – Beautiful Sedimentary Rock

tracyb — Thu, 11 Jun 2009 09:30:20 +0000

I usually tell you when I think some rocks have unique features and are just plain cool. Arkose is perhaps, one of my favorite sedimentary rocks because it is just plain pretty.

Arkose is a beautiful sedimentary rock that is typically gray, pink or red. This coarse-grained rock forms when igneous rocks break apart and the pieces travel to a river, lake or ocean. These smaller pieces are glued (cemented) together with quart or calcite. The major mineral in arkose is feldspar and the minor minerals include quartz and mica. The color of the arkose is largely controlled by the feldspars which are common in gray, white and pink. Arkose is found worldwide and is sometimes used for building materials.

Mini Me Geology offers samples of arkose both individually and in the My Rockin’ Collection! Sedimentary Rocks deluxe rock kit. Get your sample of Arkose today at www.MiniMeGeology.com!

Loess – the Earth’s most fragile rock!

tracyb — Thu, 04 Jun 2009 15:44:05 +0000

Loess is formed from fine (small) grained, windblown sediment in glacier or desert areas. Loess is made of mostly silt but may also have some small amounts of sand and clay. The major mineral present is quartz with minor amounts of feldspar, calcite, dolomite, and clay. Loess samples thed to be homogeneous throughout, which means that the grains are very similar in size, shape and color. Samples of loess also tend to be very “friable.” Friable is a term used for rocks that can be easily broken apart with very little pressure. Loess will crumble if you squeeze it too hard or drop the sample. Loess tends to be tan, pink, gray, yellow, or brown in color.

Loess is often deposited across very large areas and can be very thick. Loess which is formed in desert areas are formed when wind-blown silt accumulates in large areas. Loess which is formed in glacier areas is formed when the glaciers break down rocks into very fine grains which are then blown into deposits. Interestingly, loess which is composed of angular grains can form banks or walls which are resistant to breaking down or slumping; however, over the years, wind and water can slowly breakdown the rock. Deposits of loess can be found in

Russia, United States, China, Hungary, and Belgium.

Shop for loess and other individual rocks and minerals as well as kits at www.MiniMeGeology.com today!

Why do sandstone rocks sometimes have holes in them?

tracyb — Tue, 10 Mar 2009 14:05:42 +0000

Sandstone rocks with holes are known as porous sandstones. The porosity is formed when spaces are left during the cementation process. The cementation process is when a liquid form of a mineral such as calcite or quartz “glues” the sand grains together. The holes that are left are great places for storing water or oil. Some sandstones have more holes than other depending on the amount of calcite or quartz that fills in between the sand grains. Find out more about rocks and minerals at www.MiniMeGeology.com!