Mesa Grande is an elevated plateau or tableland. On the lower adjacent lands water is found, and ranchers--mostly Mexicans--have established themselves. Ever since the valley became settled the tableland has been a favorite playground for the children. A portion of the mesa is scantily covered with loam, where grow cacti and other specimens of dry-weather plants. A large portion of the mesa, however, is barren and the rock lies exposed, gray, mottled, or white beneath the glaring sun which shines ever from a cloudless sky. Here and there the granite and gneiss show a belt of snowy white quartz which gleams in the sunlight, forming a pleasing contrast to the darker rocks in which it is set. One day, while playing among these rocks, one of the children found a delicately tinted transparent pebble. When held up to the sun it emitted brilliant reflections and sparkled and scintillated like living flame. A cry of delight brought the other children to the spot, and then began a search for more of the pretty stones, with the result of the gathering of a dozen or more of the sparkling stones that afternoon. After this, frequent trips were made to the mesa in search of the pretty pebbles, and scarcely a house in the vicinity but contained collections of the beautiful playthings. One day a professional gem-cutter chanced to visit the valley under the mesa and in a basket of playthings he saw some of the bright pebbles. He examined the stones and learned where they had been found. Then he prospected the locality and found the gem-bearing ledges and staked claims covering the richer portions of the field. Since then some rare and valuable stones have been taken from the mines, gems equal to those of Ceylon, Brazil, or Siberia, which countries have heretofore supplied the world with these gems. The gem-bearing ledges extend over two or three hundred acres. Salt is another valuable mineral found in both the Mojave and Colorado deserts. The famous salt-fields of Salton are in the latter desert, but they have a story all their own, which will be told in another chapter. CHAPTER XII A REMARKABLE HARVEST-FIELD The most remarkable harvest-field in the United States, if not in the whole world, is located in the heart of the Colorado Desert. The spot is known as Salton, and it lies 265 feet below the level of the sea. The crop which is harvested is salt. So plentiful is the natural deposit of this necessary article that it is plowed with gang-plows, is scraped into windrows as hay is raked in the field, and, like hay, it is stacked into heaps from the windrows and is then loaded into wagons and later into cars to be carried to the reduction works three miles away. There are about one thousand acres in this saline field. When one looks upon this glittering, sparkling, and scintillating field, which lies like a great patch of snow dropped down into the midst of the burning sands of the plain, he is reminded of that passage of Scripture which says: