Fossil shells replaced by calcite found in the roads of Central Texas

The Central Texas counties surrounding Limestone County are full of beautiful ancient marine shells replaced by calcite, both massive and crystallized. Luckily for the collectors of minerals and fossils, hundreds of miles of low traffic roads in Central Texas contain a wide variety of ancient sea life replaced by calcium carbonate. They are up on the surface of gravel and dirt roads, as snowy white gravel, stretching down the country lanes.
Calcite replaced marine shell
red, yellow and blue flowers along the countryside of central texas
This area of collecting is centrally located between Interstate 35 and 45. Those highways run through Texas, connecting San Antonio, Austin, Houston and Dallas. In between this area, vast deposits of limestone of a very high quality are found and mined for agricultural and industrial use. It is often found as crushed aggregate used to cover the stone roads of back country Texas. Spiraling out of the central texas area like a web connecting new developments with well maintained farm routes, the white roads of Texas are often found to contain calcite crystals and calcite replaced marine shell fossils. Clams, Brachiopods, Turritella, Ammonites and other interesting shells are found, often with cores and voids filled with crystals of calcite.
Fossil on matrix from central Texas replaced by calcite.
Getting to a collecting location is simple! Simply pull up Google Maps and take a look at a satellite view of Central Texas. As you get closer, look out for maintained county roads, which you will see, are bright white. This white color is caused by this limestone gravel. Make a note of these roads to inspect and take a trip to Marlin, Mart, Rosebud, Franklin, Calvert, Madisonville, and Crockett. Since there is ample loose gravel, do not DIG into the road or bother to take tools with you. Loose Gravel. Mostly made up of calcite replaced shells. What an amazing collecting experience. Simply opening your car door will result in you finding a loose fossil. With smartphones, androids and iphones, simply using google maps while navigating will be all you need for a spur of the moment collecting trip. This area is a little over 3 hours from San Antonio, a quick 2 hours from Austin, Houston and Dallas. It is a PERFECT field trip in all weather besides tornadoes and snow!
google satellite view of a typical white limestone gravel backroad in central Texas
a photo of the loose gravel limestone roads and the fossil containing gravel that is scattered across Texas

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Maryland’s Chromite Deposits – A Mineralogical Monopoly

The Serpentine Barrens of Central Maryland produced an interesting landscape for a 19th century business monopoly on chromite ore, being the sole resource for world looking for new metal alloys. In addition to the facinating story of this legacy of chromite ore, the mines also produced a line of fine minerals, brucite, antigorite in fine crystals and the gem variety of serpentine known as “wiliamsite”.

Today, much of the serpentine deposits in Maryland and Pennsylvania serve as a wildlife sanctuary. The serpentine rocks and their serpentine soils were not fit for cultivation, providing a natural host for sparse grasses, scrub brushy oaks and acid loving pine trees. In addition, rare wildflowers are found only in these uncommon serpentine soils. Because these areas were never fit for cultivating, only nice flat farm land has been turned into housing developments, leaving these woodlands free from destruction. At one point in time, these areas of scrub oaks and rocky soil would have looked barren in comparison to the rich tree heavy forests surrounding that land. Now, in contrast to the houses and civilization popping up in every direction, the serpentine barrens are a rich forest

You can read this full article on this PDF, just click on the page below. This is an excerpt from the book reprint of Quarterly Magazine, which contains all sixteen issues of the magazine. You can buy the book on and it has dozens upon dozens of articles like this, written by a variety of world traveling mineral collectors. We highly suggest this book, it is a STEAL at $34.95

line pit chromite article free pdf link

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