'Art's Parts' Mg-Zn / Bi-Pb metamaterial.

Layered metallic specimen anonymously mailed to radio host Art Bell in 1996, claimed by sender 'Mr. X' to be 1947 Roswell crash debris from his grandfather. Composed of micron-thin bismuth layers alternating with thicker magnesium-zinc, plus lead and trace elements. Earlier inconclusive testing was coordinated by Linda Moulton Howe (Carnegie Science, Hal Puthoff). In 2019 TTSA acquired pieces and Howe's archive for its ADAM program under an Army CRADA. The most rigorous analysis (ORNL for AARO) found it terrestrial and unable to function as the alleged THz waveguide / antigravity device.