Gold ore type existing in nature :
In the nature, the gold ore can be existing in sand or alluvial raw material, this kind gold ore called sand gold or alluvial gold ore, the raw material is with stone, sand, gravel, soil, sticky clay, some times with magnetic iron and other minerals. The gold ore mine site is possible near river, in land , in mountain, or in the bushes,ect. The gold concentrate is visible by eye, usually size can be big nugget+2mm, or gold sand -1mm.
The other type gold ore is hard rock gold ore, the gold is existing in hard rock, such as normal stone, quartz vein above the land, or the rock gold under ground. The rock gold ore is possible to be Oxidized ore and Sulfide ore. Those two different type gold ore processing method is different.
Those two types gold ore as below pictures.