Banana Community Group
For people who sometimes feel a bit like a bloody banana! A place for validation, love, hope and warmth, a place for friendship and the sharing of dreams. A place always to feel safe and welcome..also a place for the occassional sprinkling of silliness to lighten the sometimes darkness of our days.
" What's The
Hardest Rock " ?
Hardest Rock " ?
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" Name A Term Used In Football " ?
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My 6mo twin DD's are EBF and just started rice cereal on the first. Everything has been going fine except this morning one of them had a diaper rash (lots of redness around her anus). I read this as one of the signs of an allergy. BUT I did just buy a different brand diaper yesterday (which they have used randomly before w/no issues). Do you think its the cereal or the diaper? Im ready to start...
Diamond was once thought to be the hardest and the most incompressible material on earth, either natural or man-made. Although diamond is still considered the hardest, the bulk modulus of the metal osmium has recently been found to be 476 GPa. That is over 7% more incompressible than diamond, but it is never found pure enough in nature to challenge the diamond.
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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).
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Rock hardness may be an ill-defined, multi-dimensional concept. Hardness could be its resistance to fracture, resistance to indentation, resistance to bending or twisting, resistance to abrasion, or possibly other factors.
The Mohs scale of mineral hardness typically addresses mineral hardness solely based on a minerals resistance to being scratched by another mineral. Rocks, however, are normally combinations of minerals with their own Mohs hardness, natural glass, or organically formed materials, making their hardness based on the Mohs scale inadequate in most circumstances.
Chert and quartzite are hard (not easy to fracture, resistant to weathering, and composed mostly of quartz--a hard mineral on the Mohs scale). Unweathered granites are also extremely durable because of their mineral composition and because of their interlocked crystalline structure.
Diamond, a mineral, not a rock, is the hardest mineral on the Mohs scale of mineral hardness, based on its resistance to scratching. The only mineral capable of scratching a diamond is another diamond. But as far as resistance to fracture--forget about it; diamond is easily fractured (or cleaved), a fact that allowed it to be shaped into faceted gemstones by early jewelers.