The Jewel
Scholars have said that looking at a dull jewel or pearl, or a dark glass in a dream, may indicate a warning of severe distress or choking. It may also signify losing one's mind, as the mind is a pervasive essence. It was also said that if a ruby symbolizes a friend, it might indicate a hard heart.
Per Ibn Sirin's Muntakhab al-Kalam fi Tafsir al-Ahlam