0-2g/t = waste 2-6g/t = low grade 6-10g/t = medium grade 10-15g/t = high grade >15g/t = bonanza
Results are also dependent on widths and the size of the deposit as well however there is something known as the "nugget effect". Generally known as the uneverly distribution of gold that vary in partical sizes, though generally low in grade. For this reason i dont look at anything less than 5g/t unless the thickness is there in the mine design. You can have 100 samples with the nugget effect and 50% of the samples could have no result, 45% might be low grade and 5% might have bonanza grade - consistency is important with exploration results. It is important to have a decent sized sample considering the risk involved in mining exploration. Often many company's have samples that are far too small and not indicative of the true geological surrounding.
The effect of tonnage on cost needs to be carefully evaluated for every deposit and can have a significant impact on decisions on the deposit size, profitability, mining methods and mine design - the lower the cut-off grade the better IMO. Cut-off = minimum economic grade.
I am no geologist so my knowledge is limited with gold and I mainly focus on oil and gas and my background is in finance but since I have learnt a lot from others, I enjoy sharing my knowledge with others as much as learning. I still want to learn more in regards to what widths are decent/exceptional but then again, I dont really invest in gold anymore becuase I believe that the days of a booming gold price are limited. Remember at the end of the day to remember that "grade is king" in gold and that when many large company's look to acquire companies and deposits the grade is the first point of call and often the last.
Question - does anyone have a general rule of thumb breakdown on gold sample widths - exceptional, good, average, bad, no hope??
