That's much higher than the RDA of 75-90 milligrams a day for adults. So unless you can eat plenty of fruits and vegetables, you may need to take a dietary supplement of vitamin C to gain all the benefits, Moyad says. He suggests taking 500 milligrams a day, in addition to eating five servings of fruits and vegetables.
Owner of Jones Mineral Cabinet, Geology and Paleontology Supervisor, interested in Earth and Planetary sciences. Intrusive igneous rock is formed from solidified magma below the surface of the Earth. Intrusive rock exhibits a phaneritic texture, where the individual crystal grains are visible without magnification. Examples of intrusive igneous rocks are granite, diorite, and gabbro.
Sketch of magma deep in the earth (right): USGS Images. Intrusive vs. Extrusive Igneous rocks can be classified into two main categories: intrusive and extrusive. A trick to help kids remember intrusive and extrusive is to think of intrusive -- inside and extrusive -- exit. Intrusive rocks come from magma.They cool slowly deep in Earth's crust.ntrusive vs. Extrusive Igneous rocks can be classified into two main categories: intrusive and extrusive. A trick to help kids remember intrusive and extrusive is to think of intrusive -- inside and extrusive -- exit. Intrusive rocks come from magma. They cool slowly deep in Earth's crust.