Gemstone beryl. Gemstone pricing and value are governed by factors and characteristics on the quality of the stone. These characteristics include clarity, rarity, freedom of defects, beauty of the stone, as well as the demand for them. There are different pricing influencers for both colored gemstones, and for diamonds. The pricing on colored stones is determined by market supply-and-demand, but diamonds are more intricate. Diamond value can change based on location, time, and on the evaluations of diamond vendors. There are a number of laboratories which grade and provide reports on gemstones. Each laboratory has its own methodology to evaluate gemstones.
Geology of Zambia crystalline basement rock. These rocks are generally impermeable, but store water in 10 to 15 meter thick weathered regolith and fractures. Zambia has extensive natural resources, most famously the copper ore of the Roan Group, which gave rise to the Copperbelt region. Until the rapid decline in copper prices in the mid-1970s, copper mining formed the backbone of the economy of Zambia. Demand has picked up for copper, along with secondary production of cobalt. The country has deposits of iron, zinc, lead and tin, as well as small scale gemstone mining from basement rock. The Ndola area has emerald, aquamarine,