Since it seems no one else has answered this here, from what I've tried and what options I can see, no.
On the flip side, within the NGE, if you click the tiny menu button above the index slider and to the left of the numerical entry area, there is an extensive popout listing of various indexes that you might find useful. (Varies from stones to synthetics/plastics, etc.)
| Intel i7-5960x @ 3.8 GHz| ASUS X99-E WS | 64 GB G.Skill DDR4 2400 Ram | 4x EVGA GTX 980 Ti | Win10 Professional x64 | Watercooled