The ornamental design for a multiplefacetgemstone, as shown.
FIG. 1 is a top view of a multiple facet gemstone showing my new design;
FIG. 2 is a bottom view thereof;
FIG. 3 is a front side view thereof;
FIG. 4 is a right side view thereof;
FIG. 5 is a front and right side view thereof; and,
FIG. 6 is a left side view thereof, where the rear side view is identical thereto.
The broken line showing of an edge in FIGS. 3, 4 and 5 is included for the purpose of illustrating environmental matter and forms no part of the claimed design.