Earth is a sphere in the Quran: direct mentioning.

[Chad32]

In two positions in the Quran, verses mentioned so clearly that earth is spherical.
Here it is:

Sura 13, The Quran:
( 41 )   Have they not seen that We set upon the land, reducing it from its borders? And Allah decides; there is no adjuster of His decision. And He is swift in account.

Sura 21, The Quran:
( 44 )   But, [on the contrary], We have provided good things for these [disbelievers] and their fathers until life was prolonged for them. Then do they not see that We set upon the land, reducing it from its borders? So it is they who will overcome?

Stand over a point. Look forward. Earth seems like it is extending infinity. The end of sight is the probable explanation; not the decrease of the border due to it being round.
A sphere's border is always decreasing. Your sight might be very tough; but it can never catch the curve resulting from the decrease of borders spherically.
Moreover; there is:

Sura 39, The Quran:
( 5 )   He created the heavens and earth in truth. He wraps the night over the day and wraps the day over the night and has subjected the sun and the moon, each running [its course] for a specified term. Unquestionably, He is the Exalted in Might, the Perpetual Forgiver.

The wrapping of the night and day over is another direct indication that the plain night and day are part of, is round.

That seems like a vague way of saying the world is round. I'd give points to the quran for it, because the bible talks about a circle, or four corners, or whatever.