Revelation 9:13-14

9:13 Then the sixth angel blew his trumpet, and I heard a single voice coming from the horns on the golden altar that is before God, 9:14 saying to the sixth angel, the one holding the trumpet, “Set free the four angels who are bound at the great river Euphrates!”

Revelation 16:12

16:12 Then the sixth angel poured out his bowl on the great river Euphrates and dried up its water to prepare the way for the kings from the east.

Revelation 21:20

21:20 the fifth onyx, the sixth carnelian, the seventh chrysolite, the eighth beryl, the ninth topaz, the tenth chrysoprase, the eleventh jacinth, and the twelfth amethyst.

Revelation 6:12

6:12 Then I looked when the Lamb opened the sixth seal, and a huge earthquake took place; the sun became as black as sackcloth made of hair, and the full moon became blood red;