Are considered to be the building blocks of rocks fossile fuels ores minerals none of the above characteristics that can be observed or measured without changing the matter’s identify are called chemical properties. true false minerals are very useful to us. which of the following is a false statement? pyrite is an ore of gold and is used in jewelry making. cobalt is not used in medicine. quartz is used to make glass. quartz is used to make glass. fossil fuels are not used as a good source of energy. true false the most widely used of the solid fossil fuels. coal magnesium quartz feldspar