In the novels of
Arthur C. Clarke, the first of the black
monoliths to be found by
humanity, buried in
Tycho Crater on the Moon. Like all subsequent monoliths found, it was made of an unknown black substance, and its spatial dimensions were found to have the
precise ratio 1:4:9--the
squares of the first three
integers. TMA-1 itself stood approximately ten feet in height.
The name is short for "Tycho Magnetic Anomaly-1," since, while buried, it created an unusually dense magnetic field, which allowed it to be found by explorers from Clavius Base. Once excavated from the lunar soil and exposed to sunlight, it emitted a powerful radio signal aimed at Jupiter, leading many to suspect that it was some sort of signal device. This was to affect the final plans for the Discovery mission in 2001, which resulted in the discovery of a much larger monolith at the Lagrange point between Jupiter and Io. (This monolith was exactly the same as TMA-1, only half a kilometer in length; it was christened TMA-2, but this name proved unsatisfactory to most.)
TMA-1 defied human analysis; no known sensor or cutting technology would penetrate it or reveal anything about its interior structure. In 2006, the monolith was brought to Earth and erected in the United Nations Plaza in New York City; it was intended to be a reminder that the human race was no longer alone in the universe, but, with the creation of the star Lucifer from what had been Jupiter just four years later, such a reminder seemed almost superfluous.
No one ever learned anything more about TMA-1 itself, although the discovery of an identical monolith buried under the Olduvai Gorge in 2513 (which was christened TMA-0) gave further insight into the monolith's role as a catalyst of intelligence, helping to explain the role of a larger monolith on Europa. Both TMA-1 and TMA-0 vanished without a trace in 3001, after the successful destruction of the Europa Monolith.
Source: Arthur C. Clarke, 2001: a space odyssey, 2010: odyssey two; 2061: odyssey three, 3001: The Final Odyssey