Du Baojun's Agate Pebble Museum

　　Teacher Du Baojun, who is over seventy years old, is known as a "pebble enthusiast." She has collected more than 500 colorful and uniquely patterned agate pebbles, ranging in size from as large as a bowl to as small as a bean, showcasing a world of beauty. Her private agate pebble museum is open year-round free of charge to local youth, and her story has been included in Shanghai’s newly published Encyclopedia. Teacher Du Baojun’s agate pebble collection has achieved five “firsts” and four “uniques.”

　　Agate pebbles are the general term for the pebbles found within the Yuhuatai gravel layer, with a wide variety of types. Here's an introduction based on their mineral composition:

　　1. Agate-quality agate pebbles: These are crystal-clear, rich in color, and feature varied patterns. Also known as “Yuhuatai agate,” they are considered the finest among agate pebbles.

　　2. Quartz-quality agate pebbles: Formed through the weathering and abrasion of vein quartz, quartzite, and quartz sandstone, these are the most numerous in the gravel layer. Those that are purely transparent are called “crystal” agate pebbles.

　　3. Jasper-quality agate pebbles: Composed mainly of chalcedony, fine-grained quartz, and iron oxide, they come in red, yellow, green, mixed colors, and patterns. The highest quality resembles brocaded jasper.

　　4. Opal-quality agate pebbles: These have a fine, smooth texture and a soft luster, offering great aesthetic appeal. Most opal pebbles in Yuhuatai are common opals, but there are also precious opals, known as gem-like “opals” or “欧白石.”

　　5. Flint-quality agate pebbles: Black in color and hard in texture, they were used by ancient people to create fire through friction and were called “fire stones.” They could also leave marks on metal and were thus referred to as “touchstones.”