Sigma

Sigma is a Greek letter, written as Σ in uppercase and σ in lowercase. It is often used in mathematics and science. It might be depicted as a symbol carved in stone, or written in ink on a piece of vintage parchment. The surroundings could be a university classroom or a scientist's study, filled with books, equation-filled chalkboards, and other scientific instruments. The letter itself can be represented in a bold, calligraphic style, focusing primarily on the details and intricacies of its shape. The composition of the picture might be focused on this letter, but the surroundings would also play an important part to depict the academic or scientific context.