RE: 2025 gold stock6 Jan 2025 17:29
Just for info, as a fyio
The highest quality gold ore can contain more than 20 grams of gold per tonne (g/t). Some examples of high-grade gold ore deposits include:
Fosterville Mine: Located in Australia, this mine is known for its high gold grade
Macassa Mine: Located in Canada, this mine is known for its high gold grade
Hishikari Mine: Located in northern Kagoshima Prefecture, Japan, this mine has been producing gold since 1985 and has a grade of around 20 grams of gold per tonne of ore
The grade of gold and the composition of the ore that can be excavated differ between underground and open-pit mines. The World Gold Council defines 8–10 grams per tonne as "high-quality" and 1–4 grams per tonne as "low-quality" for underground mining.
The concentration of gold in ore is measured in grams of gold per tonne of ore (g/t). This unit is obtained from drilling results, which involve extracting core samples from the Earth's subsurface.
2nd one
The grade of gold, and composition of the ore that can be practically excavated, are different for open-pit and underground mines. The grams per tonne for a low grade open-pit is then different for underground mining.
Technically speaking, the highest grade of gold would be nuggets, which are some of the only naturally occurring deposits of gold. Even these tend not to be pure 24 carat gold, but are certainly the highest grade of gold found naturally.
For underground mining, the World Gold Council defines between 8 and 10 grams per tonne as ‘high-quality’, and 1 to 4 grams per tonne as ‘low-quality’. There is no exact definition of what is considered as high or low grade. The list below is therefore a rough guide to what may be expected.
Open Pit:
Low grade 0 - 0.5 gold grams per tonne
Average grade 0.5 - 1.5 gold grams per tonne
High grade 1.5 + gold grams per tonne
Underground Mine:
Low grade 0 - 5 gold grams per tonne
Average grade 5 - 8 gold grams per tonne
High grade 8 + gold grams per tonne
'Bonanza' grade Troy Ounces (31.1 grams) per tonne
Reliable up-to-date figures for grades of gold produced by various mines are difficult to find. The US Fire Creek underground mine in Battle Mountain, Nevada, has consistently produced high grade ore. In 2015, ore from the mine had an impressive density of 44.1 grams per tonne, putting it very high on the scale, and potentially the highest grade of gold currently being mined.
In the same year, the Macassa mine in Kirkland Lake, Ontario came second, and far below with 22.2 grams per tonne.
The grade of gold being mined however, is only one of many factors that impacts upon the profitability of a mine. Besides the composition and depth of the ore there are also labour costs, technological investment and management factors to consider. Plus, mines are subject to many national and political influences.
Just a copy and paste not a post