Allotropes of carbon dispersion of light of diamond make it useful for both industrial applications and jewelry. Diamond is the hardest known natural mineral. This makes it an excellent abrasive and makes it hold polish and luster extremely well. No known naturally occurring substance can cut (or even scratch) a diamond, except another diamond. The market for industrial-grade diamonds operates much differently from its gem-grade counterpart. Industrial diamonds are valued mostly for their hardness and heat conductivity, making many of the gemological characteristics of diamond, including clarity and color, mostly irrelevant. This helps explain why 80% of mined diamonds (equal to about 100
The Hardest Part (Coldplay song) Weekly" review of the album, music contributor David Browne wrote that the song "is imbued with the sense of regret and letting go that we've heard from the band before, but with added musical muscle." Michael Hubbard of MusicOMH wrote: "'A Message' and 'The Hardest Part' sound like companion pieces, both big songs." Critic Kelefa Sanneh of "Rolling Stone" noted that the song gets "less catchy as it goes along". Adrien Begrand from PopMatters wrote that "The Hardest Part" is a "pleasant slice of R.E.M. style pop." Cameron Adams of the "Herald Sun" reported that the song sounded "like the