59 results for igneous

Everybody knows rocks are sedimentary, igneous, or metamorphic.   But did you know there are scientist who actually specialize in each one of the 3 varieties? They spend their time studying and ...

Previously we talked about the study of the first 2 types of rocks-sedimentary and igneous. You can read them here- Sedimentary Rocks or Igneous Rocks. The third type of rock is Metamorphic Rock. Met ...

Fluorite is a calcium fluoride crystal with a hardness of 4. Fluorite has a perfect cleavage (meaning it will break easily along a flat plane). It forms in massive, cubes, or isometric crystals a ...

Rhode Island is one of the worst states for finding gem grade rocks and minerals. Once a plain not much above sea level, Rhode Island has been uplifted and its surface covered by stream action into ...

Virginia though small, produces a wide variety of rocks, minerals, fossils and metals. Drowned valleys along the coastal plain of Virginia form long bays and, in the southeast, swamps such as the Gr ...

Rhyolite is an extrusive igneous rock formed as a deposit of volcanic ash. The ash becomes rock after being exposed to extreme heat and pressure. Iron oxide stains create the beautiful patterns.&n ...

Serpentine is a metamorphic rock. It was formed when water from magmas metamorphosed previous igneous or sedimentary rocks. Serpentine is a magnesium silicate mineral. Serpentine has a hardness o ...

New Hampshire has a large variety of rocks and minerals. This is due mostly to the pegmatites that comprise a large portion of New Hampshire's surface. The igneous and metamorphic rocks were worn d ...

Finding rocks and minerals in Maryland can be challenging. A lot of the good hunting areas, where rocks and minerals may be found, are heavily vegetated. The easternmost part of the state of Maryla ...

Illinois is not known for producing many gemstones or minerals. But Illinois was the leading producer of fluorite in the United States for many years, and the mineral was named the official state mi ...

  Louisiana is not known as a great place to find rocks and minerals. It is completely made up of sedimentary rocks. There are no outcrops of metamorphic or igneous rocks. Much of Louisiana h ...

New Jersey's has a rich mining history. The northwest corner of New Jersey contains the famous Delaware Water Gap, where the Delaware River has cut through the Kittatinny mountain range of the Appal ...