18 And the building of the wall of it was of jasper: and the city was pure gold, like unto clear glass.
The wall is jasper. In antiquity jasper was usually considered to be green and likened to an emerald while today it includes a stone of red, yellow, and brown as well. Other mentions of jasper in Revelation are;
Revelation 4:3 And he that sat was to look upon like a jasper and a sardine stone: and there was a rainbow round about the throne, in sight like unto an emerald.
Revelation 21:11 Having the glory of God: and her light was like unto a stone most precious, even like a jasper stone, clear as crystal;
Revelation 21:19 And the foundations of the wall of the city were garnished with all manner of precious stones. The first foundation was jasper; the second, sapphire; the third, a chalcedony; the fourth, an emerald;
Pure and clear are synonyms in this verse giving us the meaning of both. See again that this is done later.
Revelation 22:1 And he shewed me a pure river of water of life, clear as crystal, proceeding out of the throne of God and of the Lamb.
The city is pure gold, without imperfection. Here are other references to pure gold.
2Chronicles 3:4 And the porch that was in the front of the house, the length of it was according to the breadth of the house, twenty cubits, and the height was an hundred and twenty: and he overlaid it within with pure gold.
2Chronicles 9:17 Moreover the king made a great throne of ivory, and overlaid it with pure gold.
A glass that you can see through is also without imperfections.
19 And the foundations of the wall of the city were garnished with all manner of precious stones. The first foundation was jasper; the second, sapphire; the third, a chalcedony; the fourth, an emerald; 20 The fifth, sardonyx; the sixth, sardius; the seventh, chrysolite; the eighth, beryl; the ninth, a topaz; the tenth, a chrysoprasus; the eleventh, a jacinth; the twelfth, an amethyst.
Precious stones like these cover the priest’s breastplate of judgment in Exodus 28 and in Satan/Lucifer’s clothing in Ezekiel 28.
Exodus 28:17 And thou shalt set in it settings of stones, even four rows of stones: the first row shall be a sardius, a topaz, and a carbuncle: this shall be the first row.
Eze kiel 28:13 Thou hast been in Eden the garden of God; every precious stone was thy covering, the sardius, topaz, and the diamond, the beryl, the onyx, and the jasper, the sapphire, the emerald, and the carbuncle, and gold: the workmanship of thy tabrets and of thy pipes was prepared in thee in the day that thou wast created.
Be careful, if studying what these individual stones might represent in reading back modern definitions of them into the Bible, which would have defined them by ancient definitions as I explained regarding jasper. Think of them as precious stones like rubies and emeralds and remember that quibbling over definitions today and reading them back into the Bible like reading Linnaeus’ taxonomic classifications of creatures back into the Bible, which are modern definitions, will lead to a dead end. The great fish or whale, because of its large size, was a specially prepared creature and in the Bible whale does not refer to a marine mammal of the order, Cetacea, but to a large sea creature. Read Jonah 1:17; Matthew 12:40; and Genesis 1:21. Keep that in mind when you try to read back modern definitions into the Bible. God couldn’t care less about your labeling and definitions created for your own benefit.
This also brings to mind some of the problems with modern science. Such designations and classifications are merely social constructions designed to place things in categories in our own minds and do not have a necessary reality in the physical universe. In the same regard philosophers of science have noted that for some experimental scientists who deal in real, tangible evidence that some things that cannot be seen with the naked eye like photons and electrons might not even exist but are, “fictions, logical constructions, or parts of an intellectual instrument for reasoning about the world.”(20)
My point is when you are reading the words mammal or reptile, do not read them back into the Bible, written before they came into use for science. Also, do not read the modern definitions of a precious stone and presume that the Bible must conform to what we have decided to use as a label or classification after the Bible was penned and translated.
(20) Ian Hacking, Representing and Intervening: Introductory Topics in the Philosophy of Natural Sciences (New York: Cambridge University Press, 1983), 27.