Hamilton Hill Mine, Jessieville, Garland Co., Arkansas, USA
|Latitude & Longitude (WGS84):||34° 43' 57'' North , 92° 59' 14'' West|
|Latitude & Longitude (decimal):||34.73261, -92.987395|
Ref.: Rocks & Min.:63:108; Engel(1952). A quartz mine located about 3 miles NE of Jessieville. Workings feature pits, 3 adits and 2 shafts. Mineralization is quartz veins in Womble Shale. Discovered after 1865 and worked for 25 years.
Quartz crystal mining was begun at Hamilton Hill shortly after the Civil War by William Hamilton and John Neal. Hamilton worked the deposit for about 25 years and did most of the development work. The mine workings consist mainly of three short adits, no more than 30 feet long, which were caved in 1945 ; two caved vertical shafts said to have been sunk to depths of 30 and 40 feet, respectively; and numerous small surface pits. Hamilton Hill reputedly produced the largest volume of crystals of any of the old mines in the Garland County area. It was particularly well known for producing important collector specimens.
In the summer of 1943, a few shallow surface pits were dug by John Ridgeway and George Clemmonts. It is unknown what they found at this time. George Clemmonts mined the deposit again with a small bulldozer in the 1960's with the help of a young Jim Coleman. Jim recounts collecting many truckloads of outstanding crystals and cabinet specimens of the highest quality at the time. The current whereabouts of these specimens is unknown as Jim does not have one in his personal collection. Others had mined the deposit with smaller machinery and little success in the 1970s and until 2013 no work had been done there. In early 2013 the mine was purchased by Avant Mining LLC. In early June 2013 Avant begun test digging on the old mine site with spectacular success. So far they have hit a major pocket of adularia and quartz combination specimens which are unique in quality and size for North America.
The above provided by James Zigras who is involved in the current specimen recovery areas there 
2 valid minerals.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
470 - 485.4 Ma
Age: Early Ordovician (470 - 485.4 Ma)
Stratigraphic Name: Mazarn Shale
Reference: Horton, J.D., C.A. San Juan, and D.B. Stoeser. The State Geologic Map Compilation (SGMC) geodatabase of the conterminous United States. doi: 10.3133/ds1052. U.S. Geological Survey Data Series 1052. 
Engel (1952) Quartz Crystal Deposits of Western Arkansas USGS Bulletin 973E