Carbonado in the pores that are common in carbonados, they may have been introduced after carbonado formation. Inclusions of other minerals, rare or nearly absent in the Earth's crust, are found at least partly incorporated in diamond, not just in pores: among such other minerals are those with compositions of Si, SiC, and Fe‑Ni. No distinctive high-pressure minerals, including the hexagonal carbon polymorph, lonsdaleite, have been found as inclusions in carbonados, although such inclusions might be expected if carbonados formed by meteorite impact. Isotope studies have yielded further clues to carbonado origin. The carbon isotope value is very low (little carbon‑13
What Is Art? in Tolstoy and his problems: essays. London: Grant Richards. pp. 66–101. Maude, Aylmer (1901b). “"What is Art?" - Tolstoy’s Theory of Art”, in Tolstoy and his problems: essays. London: Grant Richards. pp. 102–127. Noyes, George (1918). Tolstoy. London: Duffield. Pevear, Richard (1995). "Preface" in Tolstoy, Leo (1995 [1897]). "What is Art?" (Translated by Richard Pevear and Larissa Volokhonsky). London: Penguin. Simmons, Ernest (1973). "What is Art?", in Tolstoy. London: Routledge and Kegan Paul. pp. 175–189. What Is Art? What is Art? ( "Chto takoye iskusstvo?") is a book by Leo Tolstoy. It was completed in Russian in 1897 but first