Cathedral Quartz can be found all over the world, however these locations are known for producing some of the largest, most sought after specimens on the market. This crystal formation can be seen in many quartz specimens that come from Brazil, as well as some found in Switzerland, Madagascar and Africa. Cathedral Quartz - Occurs when a secondary crystal grows parallel to another quartz crystal formation, often leaving the cluster with a cathedral-like appearance. This rupturing results in “healing” of the crystal in a process that leaves behind a string/thread-like appearance that runs through the crystal formation. The cracks in the rock expand with the crystals, causing ruptures within the crystal from pressure. These quartz formations occur between cracks in a host rock. Faden Quartz - A type of quartz formation that’s typically found in mountainous regions, with Quetta and Northern Pakistan being the most well known deposits of these beautiful specimens. Secondary growth crystals usually surround the center crystal, sprouting out from the center crystal’s faces. Artichoke Quartz, also known as Rocket Quartz, has an opposite growth pattern, where the base of the crystal will be smaller than the termination. This quartz formation occurs in high temperature environments of which the flow solution is high in carbon dioxide. The base of the crystal will be much wider than the termination. ![]() Tessin Habit Quartz Versus Artichoke Quartz - Tessin Habit, also known as expanding quartz, is a formation of quartz where the crystals dramatically taper down towards its termination. This results in some beautiful quartz specimens known as rutilated quartz and tourmalated quartz. Rutile and tourmaline are two common minerals that quartz can grow around without interruption of the formation process. ![]() Another way inclusions can occur is when silicon-rich solutions enter a cavity that had prior crystal growths. This can occur over long periods of time (in some cases, millions of years) and in waves, sometimes resulting in quartz that displays multiple layers of zoning (phantoms). The quartz crystal continues to grow, provided the environment is still favorable, resulting in the foreign particles becoming enclosed by the overlying quartz formation. Once these particles have a moment to settle, in some cases they’ll settle on the quartz crystal. ![]() This can occur by movement of surrounding rock or just an overall change in the flow solution. Quartz with inclusions - Inclusions often occur when foreign particles find their way into the silicate-rich solution. Based on the structure and potential inclusions within the crystal, a lot can be learned about the history of its formation. The type of formation of a quartz crystal is most often dependent on the environment in which it grows. The necessary minerals for quartz formation precipitate into these cavities, depositing crystals (most often in an even layer) along the inner wall of the geode. Quartz formation within a geode - While there is yet to be a conclusion as to how geodes form, it's widely accepted that they form by means of solidification of gas bubbles (vesicles) within basaltic lava during igneous rock formation and in round cavities within sedimentary rock. In some instances, a surplus of these minerals will result in a solid vein of quartz where individual crystals can no longer be identified by the naked eye. The crystals will continue to grow as long as they're provided with the environment necessary for formation. ![]() Long crystals, also known as spears, can form in these cavities when the solution drips more from one location of the rock than the other, explaining why vugs often form a wide variety of crystal sizes in close proximity. Quartz formation within a vug/cavity - Silicon-rich solutions will deposit themselves along the walls of the rock cavities. These cavities most often occur by means of tectonic activity, hollow tubes formed by lava, dissolution (breakdown of rock resulting in cavities) or even as solidified bubbles of gas within the earth (geodes). In this environment, the silicon atoms will bond to oxygen and begin building layers that over time result in cavities lined with thousands of crystals. This combination typically occurs when water that's high in silicon content (often gained through the breakdown of the surrounding rock) seeps through cracks in rocks and ends up exposed to oxygen within cavities. Quartz is primarily made up of two elemental components, silicon (Si) and Oxygen (O), both of which are in high abundance on our planet.
0 Comments
Leave a Reply. |
AuthorWrite something about yourself. No need to be fancy, just an overview. ArchivesCategories |