514 Platinwm-bearing Rocks in the Lizard District. 
The bedrock concentrate was handed over to Mr. E. H. Davison, 
who offered to assay it. He obtained a bead of platinum of -048 mg., 
thus indicating a value of approximately *024 mg. per cubit foot. 
This small value would suggest that the concentration of platinum 
is greater on surface than near bedrock, being due very probably 
to the fact that the dunite-serpentine has only been exposed by 
denudation for a short tine, and thus no platinum placers have been 
formed. It was noted, while panning the silt, that several pebbles 
remained in the bottom of the pan with the heavy sands. These 
pebbles were always of one variety, a light green rock with a small 
proportion of metallic mineral finely interlaminated. It is believed 
by the writers that the fusion assay might reveal that the platinum 
is contained in this variety of dunite serpentine, but much further 
research is required to elucidate this poimt and others, such as 
whether the platinum exists in a minutely-divided free state or 
whether it is intimately associated with magnetite or chromite, as 
appears very probable from the very small amounts of platmum 
found in the assay. 
There still remains a very small chance of an economic deposit 
being located, as there may be economic values of platinum in the 
laminated green serpentine, and judging by the amount of this 
rock found in the alluvials there must be a large body of it existing 
in the mass from which the streams flow. 
Further research into these platinum-bearing rocks became 
impossible, owing to the writers leaving Cornwall, but there is still 
plenty of work waiting any enterprising geological student who. 
cares to spend some leisure time in examining the Lizard alluvials 
and serpentines with a view to making clearer the facts of the 
above noted interesting occurrence of platinum. 
