Ann: Trading Halt, page-58

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Producing Graphene from Natural Graphite

Graphene can be prepared from natural graphite by any of the numerous methods currently used. High-quality graphene sheets produced from natural graphite contains natural impurities, typically silicate minerals, due to its formation in silicic environments. The properties of graphene depend strongly on its structure and hence for high-tech application high-purity graphene requires high-purity graphite for its production.

Metallic impurities can, therefore, reduce the efficiency of graphene for certain applications and as a result, natural graphite may not be an ideal form of carbon for graphene.