Cities were surrounded by walls, as distinguished from "unwalled villages" (Eze 38:11; Le 25:29-34). They were made thick and strong (Nu 13:28; De 3:5). Among the Jews walls were built of stone, some of those in the temple being of great size (1Ki 6:7; 7:9-12; 20:30; Mr 13:1-2). The term is used metaphorically of security and safety (Isa 26:1; 60:18; Re 21:12-20). (See Fence.)
As Jesus left the Temple, one of His disciples said to Him, "Teacher, look at the kind of stones these buildings are made of " And Jesus responded to him, "Do you see these huge buildings? There will not be one stone left on another here that will not be thrown down."
It had a very high wall [around it], with twelve angels [stationed] at its twelve gates. The names written on the gates were those of the twelve tribes of the Israelites. There were three gates on the east side [of the wall]; three gates on the north side; three gates on the south side; and three gates on the west side. read more. And the wall of the city had twelve foundation stones, and the names of the twelve apostles of the Lamb [were inscribed on them]. And the angel who spoke to me [See verse 9] had a golden measuring stick with which to measure the city, its gates and its wall. Now the city is laid out as a perfect square; its length is the same as its width. So, he measured the city with the stick [and found it to be] fifteen hundred miles each way; its length and width and height all being the same. And he measured its wall [and found it to be] two hundred and sixteen feet [high], according to human measurements which the angel was using. The material for the city's wall was jasper, and the city [itself] was made of pure gold, as clear as glass. The foundation of the city's wall was decorated with all kinds of precious stones [Note: Not all of the following stones listed can be accurately identified today]. The first foundation stone was jasper [i.e., a bluish-colored stone]; the second was sapphire; the third was chalcedony [i.e., a translucent quartz of pale blue or gray]; the fourth was emerald; the fifth was sardonyx [i.e., an orange-colored stone similar to chalcedony]; the sixth was sardius [i.e., a reddish-colored stone also called carnelian]; the seventh was chrysolite [i.e., a yellowish- or greenish-colored stone]; the eighth was beryl [i.e., a stone of bluish-green color]; the ninth was topaz [i.e., a yellow or bluish-yellow stone]; the tenth was chrysoprase [i.e., a stone of greenish-gold color]; the eleventh was jacinth [i.e., a stone of purple or reddish-blue color]; the twelfth was amethyst [i.e., a purple- or violet-colored stone].