If you tend to mouth breathe at night, it is important to make a check for the dryness every morning. While night sleeping, it is very important to breathe through your nose. In case you neglect your mouth breathing for 7-8 hours every night, it will be difficult for you to change your breathing on a permanent basis.
Diamond is currently thought to be the hardest natural material on Earth, having a hardness of ten out of ten on the Mohs scale of mineral hardness. Diamond is made up of carbon atoms which share strong covalent bonds (where electrons are shared between atoms) and are equally spaced in a lattice arrangement.
Best Answer: Well, the hardest mineral on earth is a diamond. For rocks, which are made up of one or more minerals, the hardest are those which contain quartz. There is no single hardest rock but some of the rocks that would be very hard and strong and well-cemented quartz sandstones (a sedimentary rock), quartzite (a metamorphic rock formed from quartz sandstone) and granites or rhyolites (both igneous rocks with a lot of quartz).