DailyDirt: Harder Than Diamond (But Not As Pretty Or Available)
from the urls-we-dig-up dept
Diamond is a fascinating material. We haven't quite perfected how to make diamonds, so they're still rare -- and somewhat valuable, depending on the eye of the beholder. One aspect of diamond that everyone learns in school is that it is really, really hard. However, the title of "hardest" material might have to be awarded to other exotic substances.- Diamond is the standard for comparing the upper end of the hardness scale -- and it's a naturally occurring mineral that defines what "ultra-hard" materials are. A newly discovered form of carbon called Q-carbon is harder than diamond (pending verification), and it can be made at room temperature and pressure with lasers (though currently only as a film up to 500 nanometers thick). This synthesis method can also produce diamond-like films, too. [url]
- A material called ultrahard fullerite is difficult to synthesize, but researchers are still looking for better methods to make this stuff. Ultrahard fullerite, made of a 3D polymer of connected fullerenes, can be twice as hard as natural diamond. Similar synthesis methods might also lead to aggregated diamond nanorods -- the least compressible known material (so far). [url]
- Diamond was once the hardest known naturally occurring material, but lonsdaleite (aka hexagonal diamond) was first identified in meteorites in 1967 -- and could be harder than diamond. There are a few other "harder than diamond" candidates, too, but they're not naturally occurring. Lonsdaleite is "theoretically" harder than diamond, but natural samples vary in quality and many are softer than diamond. [url]
Filed Under: aggregated diamond nanorods, allotrope, carbon, diamond-like, diamonds, hexagonal diamond, lonsdaleite, materials, q-carbon, ultrahard fullerite, ultrahard materials