Patuxent River Stone | Maryland State Gem

Effective October 1, 2004, the Patuxent River Stone became the State Gem of Maryland (Chapter 272, Acts of 2004; Code General Provisions Article, sec. 7-324).

The Patuxent River Stone is actually an agate, a cryptocrystalline form of quartz. Found only in Maryland, the Patuxent River Stone's colors of red and yellow reflect the Maryland State Flag.

The Patuxent River Stone listed is believed to be a Patuxent River Stone due to the location it was collected its physical description.