A sample of basaltic rock from a lava flow in New Mexico serves as a calibration target carried on the front of NASA’s Mars rover Curiosity for the rover’s Canadian-made Alpha Particle X-Ray Spectrometer instrument. This image of the APXS calibration target was taken by the rover’s Mars Hand Lens Imager during the 34th Martian day, or sol, of Curiosity’s work on Mars (Sept. 9, 2012). The image has been rotated to compensate for the tilted orientation of the camera when it was taken.
The prepared slab of well-characterized dark rock collected near Socorro, N.M., is held in a nickel mounting. The circular opening revealing the rock is about 1.4 inches (3.5 centimeters) in diameter.
Probably held in place with fire-roasted cement made from Hatch chiles.
Eideard 
“Scientists studying possible connection between New Mexico rocks and life on Mars” (Oct 8, 2020) https://www.krqe.com/news/new-mexico/scientists-studying-possible-connection-between-new-mexico-rocks-and-life-on-mars/
“New Mexico badlands help researchers understand past Martian lava flows” https://phys.org/news/2020-04-mexico-badlands-martian-lava.html
“Badlands 200 million miles apart: one in New Mexico and the other on Mars : Rounded hills in Gale Crater on Mars are made of sediments similar to those in the bedrock of the Bisti/De-Na-Zin wilderness in New Mexico” https://altamontenterprise.com/opinion/columns/back-roads-geology/09062018/badlands-200-million-miles-apart-one-new-mexico-and