Porphyritic Trachyte Composition and Formation
Porphyritic trachyte rocks have large, well-formed sanidine, plagioclase, and sometimes amphibole, biotite, or pyroxene crystals in a fine-grained matrix. The
Rocks
Porphyritic Phonolite Formation and Uses
Porphyritic phonolite or phonolite porphyry has well-formed, large leucite, nepheline, and alkali feldspar crystals in a fine-grained matrix. The larger
Purple, Red, or Roman Imperial Porphyry
Purple, red, or Roman Imperial porphyry refers to reddish to purplish porphyritic rocks highly-priced during the antiquity age by Romans
How to Crack, Break or Open a Geode Like a Pro
Would you like to know how to open a geode? The common ways are smashing it, using a crack hammer
Where to Hunt for Geodes in Illinois
The best places to find geodes in Illinois are Warsaw, Hamilton, and Nauvoo, which are areas in western Illinois that
What Are Geodes? Their Uses, Colors, and Mineral Crystals?
Geodes are hollow or partially filled, roughly spherical structures, globular or oblate spheroidal discrete bodies or structures lined with mineral
How Are Geodes Formed in Nature?
Is your question how are geodes formed in nature? The simple explanation is the process involves 1) cavity formation and
Geodes vs. Thundereggs, Nodules, Concretions, and Vugs
Since they resemble each other, it is good to discuss geodes vs. thundereggs, nodules, vugs, concretions, and other similar structures
What Are Lithophysae and How Do They Form
Lithophysae (singular lithophysa) are roughly spherical to lenticular-shaped structures with onion-like shells and a hollow center. These structures, which occur
Diorite Texture, Composition and Uses
Diorite is a coarse-grained intermediate plutonic rock. Intermediate are rocks whose composition lies between felsic and mafic. Felsic rocks are