The upper gravel is pierced, the covering crust is reached and broken through, and the nellan being shovelled into conical baskets and washed to free it from the sand, the residue is carefully searched for whatever rounded crystals and minute gems it may contain.
[Footnote 1: A very interesting account of _Gems and Gem Searching_, by Mr.WM.STEWART, appeared in the _Colombo Observer_ for June, 1855.] It is strongly characteristic of the want of energy in the Singhalese, that although for centuries those alluvial plains and watercourses have been searched without ceasing, no attempt appears to have been made to explore the rocks themselves, in the debris of which the gems have been brought down by the rivers.

Dr.Gygax says: "I found at Hima Pohura, on the south-eastern decline of the Pettigalle-Kanda, about the middle of the descent, a stratum of grey granite containing, with iron pyrites and molybdena, innumerable rubies from one-tenth to a fourth of an inch in diameter, and of a fine rose colour, but split and falling to powder.

It is not an isolated bed of minerals, but a regular stratum extending probably to the same depth and distance as the other granite formations.
I followed it as far as was practicable for close examination, but everywhere in the lower part of the valley I found it so decomposed that the hammer sunk in the rock, and even bamboos were growing on it.

On the higher ground near some small round hills which intercept it, I found the rubies changed into brown corundum.

Upon the hills themselves the trace was lost, and instead of a stratum there was merely a wild chaos of blocks of yellow granite.