First, thank you for all the technical expertise that you have been sharing with the forum. I for one certainly appreciate it.

I have spent some time studying two of your posts today (Chrome Ore Pricing-An Overview and Metal Equivalents) in an effort to increase my level of knowledge regarding chromite.

While I understand much of what you posted, I am struggling with comprehension regarding the relationship between the Cr2O3 assay and the wt % of the chrome-bearing spinel in the sample.

Two excerpts from your posts today are as follwos:

However, geologists use the term “chromite” in a wider sense, referring to “chrome-rich or chrome-bearing” spinels. Thus, the Cr2O3 assay of a sample of rock, reflects the wt % of the chrome-bearing spinel in the sample. If for example, the individual chrome spinel grains in a sample uniformly contain 51% Cr2O3, then the maximum assay of the sample can only be 51% Cr2O3 and that will occur if the sample is 100% chrome spinel. If the sample assays 40% Cr2O3, then the % chrome bearing spinel in the sample is proportionately less.

Lets look at BB1. From microprobe analyses of the chromite we know that it contains 35.5% Cr (51.9% Cr2O3)with a Cr:Fe ratio of 1.72. Hence, it contains 20.6% Fe. Combined Cr+Fe=56.1%. One drill core intersection assay gave 39.1% Cr2O3==>75 wt% chromite.

Try as I might, I cannot see the relationship between 39.1% Cr2O3 and 75 wt% chromite. What am I missing here?

Thanks in advance geoprof and again I appreciate the education (as I am sure many others do s well).

Cheers,

Milsy1