The ornamental design for a stone for jewelry, as shown and described.
FIG. 1 is a front elevational view of a stone for jewelry showing my new design therefore with portions shown in broken line, forming no part of the design;
FIG. 2 is a bottom plan view thereof;
FIG. 3 is a top plan view thereof;
FIG. 4 is a side perspective view thereof;
FIG. 5 is an opposite side perspective view thereof; and,
FIG. 6 is a rear elevational view thereof.
The broken line showing in FIGS. 1, 2, 4, 5 and 6 are for the purpose of illustrating environmental matter and forms no part of the claimed design.