Precious Stones: Pearl
Source: TTT
Job 28:18
Coral and quartz are unworthy of mention; the price of wisdom is beyond rubies.
Matthew 13:45, 46
Again, the kingdom of heaven is like a merchant in search of fine pearls. / When he found one very precious pearl, he went away and sold all he had and bought it.
Revelation 21:21
And the twelve gates were twelve pearls, with each gate consisting of a single pearl. The main street of the city was pure gold, as clear as glass.