Proverbs 31:10 --"Who can find a virtuous and capable wife? She is more precious than rubies."
Verse 10 begins "Who can find a virtuous and capable wife?" I believe this is mostly a rhetorical question; however, the Bible explains that only God is capable of finding a man a wife such as this.
You cannot buy virtue, you can only learn through faith and wisdom from knowing God.
In the very first verse of this description of a noble wife, we can see that only God can provide these attributes. Only God can guide a man to find a capable woman such as this, and only God can guide a woman to become like this through faith and obedience.
Verse 10 continues, "She is more precious than rubies." To say that she is more precious than rubies goes far beyond the material value of the precious, rare gem.
Proverbs 3:15 --"Wisdom is more precious than rubies; nothing you desire can compare with her."
Proverbs 8:11 and Proverbs 20:15 also state that wisdom is greater than rubies.
Since wisdom is more precious than rubies and the woman is more precious than rubies, therefore, you can conclude that the woman is extremely wise. Nothing you desire can compare with her -- a wise woman.