I doubt you're ever seeing a single layer from a pencil. "Although graphene is probably produced every time one uses a pencil, it is extremely difficult to fin

I doubt you're ever seeing a single layer from a pencil. "Although graphene is probably produced every time one uses a pencil, it is extremely difficult to find small graphene crystallites in the “haystack” of millions of thicker graphitic flakes which appear during the cleavage. In fact, no modern visualization technique including atomic-force, scanning- tunneling, and electron microscopies is capable of finding graphene because of their extremely low throughput at the required atomic resolution or the absence of clear signatures distinguishing atomic monolayers from thicker flakes." -- Making Graphene Visible https://www.physics.purdue.edu/quantum/files/CarbonNano/make-graphene-visible.pdf https://www.physics.purdue.edu/quantum/files/CarbonNano/make..., which shows it can be made visible by preparing it on an appropriate substrate. More here, where the answer is both "no", and "yes, if it's big enough": https://www.quora.com/unanswered/Is-graphene-visible-to-the-human-eye https://www.quora.com/unanswered/Is-graphene-visible-to-the-...