A young scientist tells you that she has a metamorphic rock sample that was made from clay sediments. She explains that it was probably created in high temperatures underground that were right around 800 degrees Celsius. She is sure though that the rock was created twenty kilometers (20 km) underground as it came from a known sampling from the USGS. She thinks the sample is gneiss . You look at her with a questioning grin and then proceed to tell her that there is a problem.