Across
- 2. "clearly" understandable
- 10. Flash!
- 13. lustrous with a rainbow of colors
- 14. like all metals and gemstones
- 15. searingly bright; dazzling
- 17. just like glass
- 18. radiant with light
- 19. in a different light, a different color
- 20. flowering
Down
- 1. like an opal
- 3. burning hot and bright
- 4. make some waves
- 5. M&Ms aren't; ice cream is
- 6. make it dirty
- 7. spectral (but not ghostly)
- 8. glow-in-the-dark
- 9. your shower door, hopefully
- 11. like a beautiful mountain lake
- 12. more than "fulgent"
- 16. like dishwater or a small pond
- 18. softly radiant