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Diamond is the hardest known material to date, with a Vickers hardness in the range of 70–150 GPa. ... usually alkali or alkaline earth metals or their nitrides, ...
Manufacturers use its alloys with platinum, iridium, and other platinum-group metals to make fountain pen nib tipping, electrical contacts, and in other applications that require extreme durability and hardness. [12] Osmium is among the rarest elements in the Earth's crust, making up only 50 parts per trillion . [13] [14]
Tungsten is mainly used in the production of hard materials based on tungsten carbide (WC), one of the hardest carbides. WC is an efficient electrical conductor , but W 2 C is less so. WC is used to make wear-resistant abrasives , and "carbide" cutting tools such as knives, drills, circular saws , dies , milling and turning tools used by the ...
Thermal conductivity of natural diamond was measured to be about 2,200 W/(m·K), which is five times more than silver, the most thermally conductive metal. Monocrystalline synthetic diamond enriched to 99.9% the isotope 12 C had the highest thermal conductivity of any known solid at room temperature: 3,320 W/(m·K), though reports exist of ...
Diamond was the hardest known naturally occurring mineral when the scale was designed, and defines the top of the scale, arbitrarily set at 10. The hardness of a material is measured against the scale by finding the hardest material that the given material can scratch, or the softest material that can scratch the given material.
Chromium is the third hardest element after carbon and boron. Its Mohs hardness is 8.5, which means that it can scratch samples of quartz and topaz , but can be scratched by corundum . Chromium is highly resistant to tarnishing , which makes it useful as a metal that preserves its outermost layer from corroding , unlike other metals such as ...
Like most metals, finely divided iridium powder can be hazardous to handle, as it is an irritant and may ignite in air. [66] Iridium is relatively unhazardous otherwise, with the only effect of Iridium ingestion being irritation of the digestive tract . [ 106 ]