Instead of bending over to strike the rock, it is often better to get down on one knee and strike the rock with a downward motion. So, hit the rock at an angle at which a bounce will not send the head of the rock hammer into your shin. If you must use your hammer on quartzite, be sure that you are wearing impact-resistant goggles, gloves, long sleeves, long pants, and sturdy shoes.Ī sharp hammer blow often bounces off. That small piece is usually more than enough.Īvoid hitting quartzite with a forceful blow of a rock hammer. If a freshly broken piece is needed for examination, they break off a small protrusion with a light tap. Wise geologists, who have memorable experiences with quartzites, hit them with a rock hammer only when necessary. Much of the 'aventurine' sold for lapidary use is actually quartzite. These pieces of rough average about 1 inch across and were sold for making tumbled stones in a rock tumbler. 'Aventurine': Pieces of green, yellow, and reddish orange ' aventurine' from India. This contributes to the inconsistency in the ways that geologists use the word 'quartzite.' It is often called 'quartzite' when rock units above and below it are clearly sedimentary. It would be better called 'sandstone' in other areas.īetween these areas, the names 'quartzite' and 'sandstone' are used inconsistently and often guided by habit. The transition of sandstone into quartzite is a gradual process.Ī single rock unit such as the Tuscarora Sandstone of the central Appalachians might fully fit the definition of quartzite in the parts of its extent where its quartz grains have been metamorphosed into a durable interlocking mass. It is often difficult or impossible to differentiate quartz arenite from quartzite.

The name 'quartz arenite' is a more appropriate and less confusing name for these rocks. This usage is falling out of favor but remains in older textbooks and other older publications. Today most geologists who use the word 'quartzite' are referring to rocks that they believe are metamorphic and composed almost entirely of quartz.Ī few geologists use the word 'quartzite' for sedimentary rocks that have an exceptionally high quartz content. Geologists have used the name 'quartzite' in a few different ways, each with a slightly different meaning. John, used here under a Creative Commons license.

The quarry is in the Elmers Rock Greenstone Belt, Wyoming. This specimen measures about 7 centimeters across and was collected from a small abandoned quarry where the flaggy rocks were produced and cut for use as decorative stones. Other impurities can cause quartzite to be yellow, orange, brown, green, or blue.įuchsitic Quartzite: A specimen of quartzite that contains significant amounts of green fuchsite, a chromium-rich muscovite mica. Some rock units that are stained by iron can be pink, red, or purple. Quartzite is usually white to gray in color. This is a characteristic that separates true quartzite from sandstone. It is so tough that it breaks through the quartz grains rather than breaking along the boundaries between them. The interlocking crystalline structure of quartzite makes it a hard, tough, durable rock. Photograph by Jackdann88, used here under a Creative Commons license. The interlocking nature of the grains gives quartzite its incredible durability. The important thing to notice is how they fit together in a tight interlocking network. The quartz grains in this view range in color from white to gray to black depending upon their optical orientation. Quartzite Under a Microscope: A specimen of the Bo Quartzite collected near South Troms, Norway, observed through a microscope in thin-section under cross-polarized light.

Rose quartz rock