Question #1

In order to explain to my friend how to tell if the material is a mineral or a rock, I would start off with the differences between rocks and minerals. Minerals make up rocks, but rocks do not make up minerals. Minerals are mined from Earth, whereas rocks are exposed due to weathering or wearing away and by transportation from wind, water, ice, and moving plates. Minerals are inorganic whereas rocks are organic, formed from the remains of living things. To apply these ideas to the material my friend found, I would tell her to check for any fossil remains in the material. If there is a fossil present you can automatically tell the material is a rock, since rocks are formed from the remains of living things. If there are no fossil remains, I would tell my friend to get more specific in what the material looks like. A mineral is a homogeneous, uniform, solid. A mineral can be a chemical element or be composed of elements in set ratios. If the object that was found has many parts that contain different colors and the object doesn’t look like it has a set ratio of chemical compounds, I would tell my friend the object is a rock. If it were still too hard to determine that the object is a rock, I would look at the specific properties of the most common minerals (only about a dozen are found commonly on the surface of Earth) so that the object can be categorized.
It’s hard to tell whether something is a mineral or a rock. Both rocks and minerals can be dark colored or light colored, rough or smooth, react to HCl, contain crystals, etc. Some tips to help students feel insured that they can tell minerals apart from rocks would be to: look for a crystalline structure, check for any fossils or plant or animal remains, check to categorize the object as homogeneous and uniform rather than being easily able to pick out separate parts, and to try and see if anything gives away how the object was formed. If the object has a repeating crystalline structure, whether it is hexagonal, cubic, etc, the object is a mineral. If there are any fossil or plant remains present in the sample, it is a rock. If the object is evenly mixed and individual parts cannot be seen, it is a mineral. If the object has many different colors and crystal sizes it is not considered homogenous and can be distinguished as a rock.