Pearls were graded according to shape, size, and color.  The rare ones were very round; such as would roll on a table top without noticeable wobble.  Ones larger than an olive were rarer, although they have been found as large as a chicken's egg.  The color and luster were of great importance.  The color changed with the angle of light and view point. The richer variations of color play were called oriental iridescence.   A pearl merchant in the Eastern Orient wrote that in the gold, silver, and jewelry districts of major cities there were known prices for various sorts of pearls based on size, shape, and color.  A very rare pearl was of much greater value and being so rare that there were none in the district, its price was greater than all others in that area.  I have read that a thousand pearl oysters were opened to find a pearl that was marketable.  There might be one very rare pearl in hundreds of thousands of pearl oysters.  Emperors gave their wives and daughters fine pearls.  People with great wealth exhibited their pearls and considered them to be investments of great value.  During the 20th century; artificial pearl cultivation lowered the price of pearls.  

Those seeking God's blessings and care might find it to be greater than any other thing and give much for the love of God.

Matthew 7 (ASV)

 

Peter and Paul (letter to Timothy) wrote letters counseling women to avoid making an extravagant display of clothing and jewelry on the outside, but to be of great value on the inside.