The word(s) "darkness" appears 25 time(s) in 23 verse(s) in Quran in Muhammad Pickthal translation.

(11) Say (O Muhammad): Who is Lord of the heavens and the earth? Say: Allah. Say: Take ye then (others) beside Him for protectors, which, even for themselves, have neither benefit nor hurt? Say: Is the blind man equal to the seer, or is darkness equal to light? Or assign they unto Allah partners who created the like of His creation so that the creation (which they made and His creation) seemed alike to them? Say: Allah is the Creator of all things, and He is the One, the Almighty.

(12) Alif. Lam. Ra. (This is) a Scripture which We have revealed unto thee (Muhammad) that thereby thou mayst bring forth mankind from darkness unto light, by the permission of their Lord, unto the path of the Mighty, the Owner of Praise,

(13) We verily sent Moses with Our revelations, saying: Bring thy people forth from darkness unto light. And remind them of the days of Allah. Lo! therein are revelations for each steadfast, thankful (heart).

(14) And (mention) Dhu'n-Nun, when he went off in anger and deemed that We had no power over him, but he cried out in the darkness, saying: There is no Allah save Thee. Be Thou Glorified! Lo! I have been a wrong-doer.

(15) Or as darkness on a vast, abysmal sea. There covereth him a wave, above which is a wave, above which is a cloud. Layer upon layer of darkness. When he holdeth out his hand he scarce can see it. And he for whom Allah hath not appointed light, for him there is no light.

(16) Is not He (best) Who guideth you in the darkness of the land and the sea, He Who sendeth the winds as heralds of His mercy? Is there any Allah beside Allah? High Exalted be Allah from all that they ascribe as partner (unto Him)!

(17) He it is Who blesseth you, and His angels (bless you), that He may bring you forth from darkness unto light; and He is ever Merciful to the believers.

(18) Nor is darkness (tantamount to) light;

(19) A token unto them is night. We strip it of the day, and lo! they are in darkness.

(20) He it is Who sendeth down clear revelations unto His slave, that He may bring you forth from darkness unto light; and lo! for you, Allah is Full of Pity, Merciful.