A Rock Sample Lab Report

Questions and Answers Rock specimen “A” is identified as marble. This sample had a white to cream color to it, which is an identifying characteristic of marble. Another characteristic is the calcite inclusion; this inclusion is seen by bubbling when exposed to a saturated citric acid solution. When viewed by the unaided eye, the grain and crystal structure is clearly seen. While marble is supposed to be a fairly soft rock, the example provided proved to be fairly durable which was tested using a small hammer. Repeated strikes with moderate force yielded only small chips. Marble is a metamorphic rock that formed from limestone with calcite inclusions that was exposed to increased heat and pressure. Like sample “A”, rock sample “B” was also a metamorphic rock. Similar to rock example “A,” rock “B” is a metamorphic rock also, called gneiss. The color scheme of the gneiss provided shows a clear banding of grey and pink coloration with some reddish inclusions. When exposed to the …show more content…
This rock sample has a greyish tincture to it. It is also found to have trace amounts of calcite included with it. This was found using the saturated citric acid solution. When exposed to this solution, the sample has very minute bubbles that formed. These bubbles could only be visible with a hand lens under close scrutiny. The rock sample did appear to have a grain structure not unlike compressed sand. These individual grains were easily separated from the main rock by the mere friction of a fingertip rubbing over the rock. Unlike all the rocks tested, this sample was very light. One of the tests subjected to this particular sample was a float test. While sample “D” did end up sinking, it attempted to float before slowly sinking to the bottom of the cup filled with water. Pumice is an igneous rock formed from quickly cooled magma (Pumice, 2014). Unlike pumice, example “E” is quite tough and