Diamond is a polymorph of graphite. Both contain carbon atoms, but they have extremely different properties because of the condition in which they are formed. Diamond is obtained after applying

Diamond and graphite are allotropes of carbon with distinct physical properties due to their atomic arrangements. While graphite is the stable form of carbon at ambient conditions, diamond is formed under extreme environments. According to scientific evidence, diamonds are synthesized by subjecting pure carbon to very high pressure and high temperature (HPHT) [1]. Natural diamonds form deep within the Earth's crust under these HPHT conditions. Laboratory synthesis using the HPHT technique typically requires pressures between 50 and 100 kBar and temperatures ranging from 1800 to 2300 K to facilitate the crystallization of diamond from carbon sources like graphite [1]. This process involves the direct conversion of sp2-bonded graphite into the sp3-bonded tetrahedral structure of diamond [4]. Although alternative methods like Chemical Vapour Deposition (CVD) exist for low-pressure growth, the standard condition for obtaining diamond from carbon polymorphs is high pressure and high temperature [1].

Sources

1. [1] Science , class X (NCERT 2025 ed.) > Chapter 4: Carbon and its Compounds > Allotropes of carbon > p. 61
2. [2] https://www.sciencedirect.com/science/article/am/pii/S2590238520302460
3. [4] https://www.sciencedirect.com/science/article/abs/pii/S0022024823000763