The bond structure of this material provides physical properties approaching those of diamond, including a hardness of over about 50 GPa, with certain species having {HEAD ~ hardness} of {TAIL ~ up to about 80 GPa} 
The bond structure of this material provides physical properties approaching those of diamond , including a hardness of over about 50 GPa , with certain species having { HEAD ~ hardness } of { TAIL ~ up to about 80 GPa }
OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH OTH HEAD HEAD HEAD HEAD HEAD REL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL TAIL