Glass

1234567891011121314151617181920
Across
  1. 4. light waves
  2. 10. regular shape
  3. 13. bouy
  4. 14. circle breaks
  5. 16. chemistry
  6. 19. dices
  7. 20. dense
Down
  1. 1. heating and cooling
  2. 2. spread
  3. 3. spoke breaks
  4. 5. light
  5. 6. amorphous sand
  6. 7. characteristics
  7. 8. sink
  8. 9. 2 refraction indices
  9. 11. bulletproof
  10. 12. suspend
  11. 15. no shape
  12. 17. in liquid
  13. 18. length of a wave