Revelation 21:18

The construction of its wall was of jasper
Jasper was the last stone in the breastplate of the high priest (Ex. Ex. 28:20; Ex. 39:13). It was also one of the stones which was Satan’s covering in the garden of God (Eze. Eze. 28:13). The light of God’s glory in her midst shines through the jasper walls (Rev. Rev. 21:11+).

pure gold, like clear glass
Pure and clear are from the same word, καθαρός [katharos] : clean, pure, free from dirt.1 Solomon’s Temple was overlaid with gold (1K. 1K. 6:22). The New Jerusalem is considered the queen in relation to the King, the Lamb. “At Your right hand stands the queen in gold from Ophir” (Ps. Ps. 45:9). See Jerusalem Married to God. The purity of the gold speaks of that which has been tested and refined by fire to remove the dross (Job Job 23:10; Zec. Zec. 13:9; 2Cor. 2Cor. 4:17-18; 1Pe. 1Pe. 1:7). Those who inhabit the New Jerusalem are now without sin. No mention is made of lesser metals, such as silver or bronze (Isa. Isa. 60:17).


1 Frederick William Danker and Walter Bauer, A Greek-English Lexicon of the New Testament and Other Early Christian Literature (Chicago, IL: University of Chicago Press, 2000), 388.