One of the few parks in the country that caters to rockhounds! And the only site where you can pay a small fee and keep any diamond and other lapidary materials you collect in the world.
Geology
Around 100 million years ago, the lazy southern coastline in what is now central Pike County, AR, suddenly exploded, creating a crater some 80 acres in size. After this eruption, small pyroclastic cones developed in the crater and spewed out ash and lapilli (small molten rock fragments)
Some of the ash mixed with sediments from the adjacent Trinity Formation, forming lake sediments on the east margin of the crater and at scattered sites across the depression. Then came a magma from deep in the earth, filling part of the depression with a lava lake. This sequence of events took awhile, but only a wink of an eye in geologic time.
The lamproite breccia tuff that formed in the explosion carried diamonds from deep in the earth (in the upper mantle) and rapidly brought these crystals to the surface. Although the lamproite magma originated from the same depth, it moved slowly enough for the magma to resorb the diamonds. Hence, it is not considered a source of diamonds at the site, either in the rock or the soil developed from it. Recent exploration demonstrated that there are some 78.5 million tons of diamond-bearing rock to sort through, so it will be awhile before the tourists and rockhounds deplete this diamond storehouse!
Mount Ida and vicinity near Hot Springs, Arkansas
Quartz, Wavellite
Granite Mountain
It's really syenite, but some of the most unusual findings in minerals have come from these quarries in Little Rock.
Fiddler's Ridge
I've collected here several times and always got what I thought was my fee-pay's worth.
