Pearl

Concise Bible Dictionary:

Ice Crystals
In Job 28:1818No mention shall be made of coral, or of pearls: for the price of wisdom is above rubies. (Job 28:18) the word is gabish, which signifies “ice” and hence “crystal.” In the New Testament μαργαρἰτης is from “to glisten, shine,” and perhaps refers to pearls, such as are discovered in shells of various species. They are mentioned three times as distinct from precious stones (Rev. 17:44And the woman was arrayed in purple and scarlet color, and decked with gold and precious stones and pearls, having a golden cup in her hand full of abominations and filthiness of her fornication: (Revelation 17:4); Rev. 18:12,1612The merchandise of gold, and silver, and precious stones, and of pearls, and fine linen, and purple, and silk, and scarlet, and all thyine wood, and all manner vessels of ivory, and all manner vessels of most precious wood, and of brass, and iron, and marble, (Revelation 18:12)
16And saying, Alas, alas, that great city, that was clothed in fine linen, and purple, and scarlet, and decked with gold, and precious stones, and pearls! (Revelation 18:16)
). They were worn as an ornament by women (1 Tim. 2:99In like manner also, that women adorn themselves in modest apparel, with shamefacedness and sobriety; not with broided hair, or gold, or pearls, or costly array; (1 Timothy 2:9)). Metaphorically the term applies to anything costly; things which should not be cast before swine (Matt. 7:66Give not that which is holy unto the dogs, neither cast ye your pearls before swine, lest they trample them under their feet, and turn again and rend you. (Matthew 7:6)). The gates of the heavenly Jerusalem were each of one pearl (Rev. 21:2121And the twelve gates were twelve pearls; every several gate was of one pearl: and the street of the city was pure gold, as it were transparent glass. (Revelation 21:21)). In the parable of the one Pearl of Great Price the Lord is represented as selling all that He had (as man and Messiah) in order to become its possessor (Matt. 13:45-4645Again, the kingdom of heaven is like unto a merchant man, seeking goodly pearls: 46Who, when he had found one pearl of great price, went and sold all that he had, and bought it. (Matthew 13:45‑46)). It implies the unique character of the church in the eyes of Christ.
Pearl Ring