The spyglass was created as a result of an experiment by Malone to view Dust like the mulefa could. Malone created two lenses with a lacquer from plants growing in the mulefa world. By applying many coats to a soft wood, and then removing the wooden backening with her Swiss Army knife and the help of an acid-like liquid used by the mulefa, she was able to create a single clear sheet of hardened amber lacquer.
As the sheet showed her a double image, similar to the mineral Iceland Spar she was previously aware of, she decided to split the sheet into two lenses and experiment with holding them apart. It was only when she accidently covered them with oil from the wheel-trees and then held them certain distance apart that she could finally see Dust. The mulefa gave Malone a tube of bamboo to which the lenses were attached, keeping them the perfect distance.
The amber spyglass allowed the human eye to see Dust, as the mulefa eye can see unaided. Malone used the telescope to observe the loss of Dust in the mulefa world.