The ornamental design for a setting for a gemstone, as shown and described.
FIG. 1 is a perspective view of a setting for a gemstone showing our new
design. The setting is shown in a position of use inserted in hair; and,
FIG. 2 is a perspective view of a setting for a gemstone showing a second
embodiment of our new design. The setting is shown in a position of use
inserted in hair.
The broken line showing of hair and gemstones in FIGS. 1 and 2 and of
portions of the setting in FIG. 2 is for illustrative purposes only and
forms no part of the claimed design.