PEA GRAVEL 50# BAG 1/8"X1/4" 50lbs. Bag 1/8" x .25" Pea Gravel. Pea gravel is able to contain moisture and protect soil from temperature and wear and tear due to its durable nature. Made from semi-rounded quartz or river rock, pea gravel is perfect for walking paths and is a wonderful complement to water features. This adaptable gravel can be used to strengthen the border of any garden and help retain water.