half an hour (Greek #2256)

Revelation
8:1   And
kai (Greek #2532)
and, also, even, so then, too, etc.; often used in connection (or composition) with other particles or small words
KJV usage: and, also, both, but, even, for, if, or, so, that, then, therefore, when, yet.
Pronounce: kahee
Origin: apparently, a primary particle, having a copulative and sometimes also a cumulative force
when
hote (Greek #3753)
at which (thing) too, i.e. when
KJV usage: after (that), as soon as, that, when, while.
Pronounce: hot'-eh
Origin: from 3739 and 5037
he had opened
anoigo (Greek #455)
to open up (literally or figuratively, in various applications)
KJV usage: open.
Pronounce: an-oy'-go
Origin: from 303 and οἴγω (to open)
the seventh
hebdomos (Greek #1442)
seventh
KJV usage: seventh.
Pronounce: heb'-dom-os
Origin: ordinal from 2033
seal
ho (Greek #3588)
the definite article; the (sometimes to be supplied, at others omitted, in English idiom)
KJV usage: the, this, that, one, he, she, it, etc.
Pronounce: ho
Origin: ἡ (hay), and the neuter τό (to) in all their inflections
sphragis (Greek #4973)
a signet (as fencing in or protecting from misappropriation); by implication, the stamp impressed (as a mark of privacy, or genuineness), literally or figuratively
KJV usage: seal.
Pronounce: sfrag-ece'
Origin: probably strengthened from 5420
, there was
ginomai (Greek #1096)
to cause to be ("gen"-erate), i.e. (reflexively) to become (come into being), used with great latitude (literal, figurative, intensive, etc.)
KJV usage: arise, be assembled, be(-come, -fall, -have self), be brought (to pass), (be) come (to pass), continue, be divided, draw, be ended, fall, be finished, follow, be found, be fulfilled, + God forbid, grow, happen, have, be kept, be made, be married, be ordained to be, partake, pass, be performed, be published, require, seem, be showed, X soon as it was, sound, be taken, be turned, use, wax, will, would, be wrought.
Pronounce: ghin'-om-ahee
Origin: a prolongation and middle voice form of a primary verb
silence
sige (Greek #4602)
silence
KJV usage: silence. Compare 4623.
Pronounce: see-gay'
Origin: apparently from σίζω (to hiss, i.e. hist or hush)
in
en (Greek #1722)
"in," at, (up-)on, by, etc.
KJV usage: about, after, against, + almost, X altogether, among, X as, at, before, between, (here-)by (+ all means), for (... sake of), + give self wholly to, (here-)in(-to, -wardly), X mightily, (because) of, (up-)on, (open-)ly, X outwardly, one, X quickly, X shortly, (speedi-)ly, X that, X there(-in, -on), through(-out), (un-)to(-ward), under, when, where(-with), while, with(-in). Often used in compounds, with substantially the same import; rarely with verbs of motion, and then not to indicate direction, except (elliptically) by a separate (and different) preposition.
Pronounce: en
Origin: a primary preposition denoting (fixed) position (in place, time or state), and (by implication) instrumentality (medially or constructively), i.e. a relation of rest (intermediate between 1519 and 1537)
heaven
ho (Greek #3588)
the definite article; the (sometimes to be supplied, at others omitted, in English idiom)
KJV usage: the, this, that, one, he, she, it, etc.
Pronounce: ho
Origin: ἡ (hay), and the neuter τό (to) in all their inflections
ouranos (Greek #3772)
the sky; by extension, heaven (as the abode of God); by implication, happiness, power, eternity; specially, the Gospel (Christianity)
KJV usage: air, heaven(-ly), sky.
Pronounce: oo-ran-os'
Origin: perhaps from the same as 3735 (through the idea of elevation)
about
hos (Greek #5613)
which how, i.e. in that manner (very variously used, as follows)
KJV usage: about, after (that), (according) as (it had been, it were), as soon (as), even as (like), for, how (greatly), like (as, unto), since, so (that), that, to wit, unto, when(-soever), while, X with all speed.
Pronounce: hoce
Origin: probably adverb of comparative from 3739
the space of half an hour
hemiorion (Greek #2256)
a half-hour
KJV usage: half an hour.
Pronounce: hay-mee-o'-ree-on
Origin: from the base of 2255 and 5610
.*
ho (Greek #3588)
the definite article; the (sometimes to be supplied, at others omitted, in English idiom)
KJV usage: the, this, that, one, he, she, it, etc.
Pronounce: ho
Origin: ἡ (hay), and the neuter τό (to) in all their inflections