Question

What is the hardest rock and what is its compressive strength (PSI)?

Asked by: Ed Mendoza

Answer

Diamond, since it is a natural mineral, would be considered a 'rock.' Diamond has a bulk modulus (reciprocal of compressibility) of 443 GigaPascals (GPa). One GigaPascal is equal to 14503.77 PSI. Therefore, the incompressibility of diamond is about 6.425 million PSI or 437,200 Atmospheres.

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.

Answered by: Scott Wilber, President, ComScire - Quantum World Corporation

Search

Loading



Click here to get
a FREE ride with Uber!


Click here to
sign up for Birchbox






Science Quote

'To myself I seem to have been only like a boy playing on the seashore, and diverting myself in now and then finding a smoother pebble or a prettier shell than ordinary, whilst the great ocean of truth lay all undiscovered before me.'

Isaac Newton
(1643-1727)
Science Sidebar | Science Education Articles
10 Ways to Keep Your Kids Interested In Science

Young children are natural scientists: they ask questions, pick up sticks and bugs outside, and are curious about the world around them. But as they get a bit older, many kids gradually lose their interest in science. They might see it as just another task at school, something that doesn't apply to their lives. Of course nothing could be further from the truth, so here are ten ways you can remind your kids that science is everywhere. Most of these are fun for adults, too! Continue reading ...

Top Selling

Here are our physics & astronomy bestsellers:
Deluxe Water Rocket Set
Mini Plasma Ball
KonusScience 5 Way Microscope Kit
3D Magnetic Field Tube
Scorpion, Ant, Wasp and Flower Bug
Alnico Bar Magnet - 6 inch Long
Solar Radiometer
Weather Station 4M Kit
Periscope
Cherry Wood Levitron

Sponsors

USC University of Southern California Dornsife College Physics and Astronomy Department McMaster University Physics and Astronomy Department