A soft, black opaque carbonaceous rock that can be used to make pencils is
Answer Details
The soft, black, opaque, carbonaceous rock that can be used to make pencils is graphite. Graphite is a form of carbon that is characterized by its slippery texture and ability to conduct electricity. It is commonly used as the "lead" in pencils due to its ability to leave a dark mark when applied to paper. While coal is also a carbonaceous rock, it is not typically used to make pencils due to its different physical properties. Lignite is a type of coal, and lead is a metal that is not commonly used in pencil-making. Therefore, the correct answer is graphite.