The presence of traces of other minerals during the formation period causes the clear quartz crystals to develop in various colors.
Quartz can be purple, yellow, rose, blue, smoky gray, or clear. Often a chalcedony kal-SED-en-e layer lies between the inner projecting crystals and the outer geode shell. This chalcedony layer consists of bands of tiny interlocking quartz crystals too small to be easily distinguished under a light microscope.
In fact, the structure of this type of quartz is so minutely developed that the material is never able to mature as actual crystals with definite outward shapes. In this banded form, the chalcedony is known as agate.
Geodes completely filled with colorful agate have been found. In recent years the term geode has been expanded to include the crystal formations found in gas cavities in volcanic rocks. Often they are filled almost entirely with banded agate chalcedony, and they range in size from microscopic to about eight inches in diameter.
The southern part of the Quitman Mountains in Hudspeth County contains the type of volcanic rocks in which these amygdules form. Geodes Spherical rocks with hollow cavities lined with crystals Photo Nylakatara - Dreamstime.
Geologists have long been challenged to explain how geodes, those mysterious spherical rocks, are formed. Geodes are a variable phenomenon, which means that they may be created in various different ways. The term geode is derived from the Greek word Geoides which means "earthlike. A geode is a round rock which contains a hollow cavity lined with crystals.
Rocks which are completely filled with small compact crystal formations such as agate, jasper or chalcedony are called nodules. The only difference between a geode and a nodule is that a geode has a hollow cavity, and a nodule is solid. Geodes begin as bubbles in volcanic rock or as animal burrows, tree roots or mud balls in sedimentary rock.
Over long time, millions of years the outer shell of the spherical shape hardens, and water containing silica precipitation forms on the inner walls of the hollow cavity within the geode. Check in limestone areas that have signs of visible drainage. Geodes are formed when water drains through a cavity in limestone left by shifting earth, a decomposing animal or washed-out areas. Areas that show erosion and existing drainage can contain geodes.
Gather the rocks that you feel may have geode content and with a chisel and a hammer, tap them gently until they open. If you don't trust yourself to correctly open the geode, take it to an expert that deals in geodes. This is where you can find the famous blue topaz crystal as well. Jasper is another beautiful crystal that you can find in many places across Texas. TIP: Opals are beautiful gemstones but you need to be careful when buying them on the internet.
There is a lot of fake opals so it is always good to know the differences between real and fake opals. Find out more in the article below:. Real vs. Fake Opal: Focus on These 6 Differences. Apart from various crystals and minerals , there are many unique fossils that you can find in Texas. You can find megalodon teeth, dinosaur bones, crinoids, echinoids, brachiopods, bryozoans, pelecypods, corals, trilobites, shark teeth, and various plants. The Mineral Wells Fossil Park is among the best places to find fossils in Texas, as it allows visitors to collect specimens.
Here there are various fossils that you can collect, including corals, clams, oysters, sea lilies, bryozoans, arthropods, and brachiopods. I f you want to find shark teeth, especially the ones of the ancient megalodon shark, you can search for them in Post Oak Creek, in Sherman.
Galveston Island, Bolivar Peninsula, Waco Lake, and Midlothian Quarry are also some great locations to find shark teeth in Texas and even ancient megalodon teeth. When it comes to finding dinosaur bones in Texas, Post Oak Creek in Sherman is again a great place to look for them. The shallow pits, creek bands, riverbeds are all excellent places to witness dinosaur remains, even footprints.
If you feel a little more adventurous, and you may want to find something trapped in amber or amber for the sake of it, you can find amber in plenty of places in Texas. Some of the best locations include the upper Aguja Formation in Terlingua, and overall the Big Bend area is filled with great places to find amber in Texas. East and South Texas are the best regions where you can find petrified palm wood. In East Texas, you find petrified palm wood in the area of creek beds and banks just east of New Caney, between Camden and Chester, or north of Lake Livingston.
Just west of Freer in South Texas, you can also find petrified palm wood. Galveston is nonetheless the best place in Texas where you can find sea glass.
TIP: Did you know you can make your own sea glass at home? Yes, and it is quite simple! Check out this step-by-step guide on how to do it in the article below:. Many native American tribes once inhabited Texas, and you can find such relics but always be sure to get permission first and adhere to the laws for the areas you are going to first. Basically, you have high chances of finding arrowheads just about anywhere in Texas, predominantly near lakes, ponds, rivers, and shallows creeks, where the natives would often hunt.
Meteorite remains known as tektites can be found in Texas. While searching for tektites, you can also find fire pearls, black diamonds, or bediasites, which are valuable. TIP: Finding meteorite is quite rare.
You have to be really lucky to find one. But do you what the rarest gemstones on Earth are? Find out what they are in the article below:. Still did not find the answer to your answers about rockhounding in Texas? Find frequently asked questions in the section below:. It would be best if you asked for permission to do so on private properties, and overall, always check up with the law if you can collect specimens in certain areas. Collecting gold on federal land can be done with permits, and when it comes to state and private lands, you also need to ask for permission or receive a permit from the Gold Prospectors Association of America.
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