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Which three forms of arsenic were recognized by the 11th century?

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A labeled diagram of the periodic table entry for arsenic, showing its atomic number 33, symbol As, atomic weight 74.921595, electron configuration, and classification as an other nonmetal. Additional icons indicate arsenic is solid at room temperature, has a rhombohedral crystal structure, and weakly acidic oxides. — arsenic Properties of arsenic.

By the 11th century, three forms of "arsenic" were recognized. These were:

White: Arsenic trioxide ( $A s_{4} O_{6}$ )1
Yellow: Arsenic trisulfide ( $A s_{2} S_{3}$ ), also known as orpiment1
Red: Arsenic sulfide ( $A s_{4} S_{4}$ ), also known as realgar1

While these compounds were known for centuries, arsenic was not clearly recognized as a distinct chemical element until much later, with the first authentic report of the free substance occurring in 1649.1