Ten samples of ore from the deposits near Camaguey contain from 27% to 36% of chromic oxide. Only two produced less than 30% while a few ran above 35%. This is a low grade ore but is suitable for certain purposes. If it should require concentration, sufficient water is available in small streams within a mile of the deposit.
Twenty miles north of Camaguey, near the eastern end of the Cubitas iron ore beds, are several other deposits of chrome that were examined by A. C. Spencer of the United States Geological Survey in 1907. All of these denoted noteworthy quantities of chrome float, apparently of high grade, and the occurrence of tabular bodies of chrome from one to five feet in width. On one claim boulders of chrome ore are distributed over a belt of some 1700 feet, and on another, fragments of ore are found in an area 150 by 250 feet. On still another claim, five deposits lie within an area measuring 1200 by 3000 feet. One of these seems to be continuous for something over 900 feet.
Both chrome and manganese are scattered throughout various sections of Oriente and the largest deposits of these minerals as well as those of iron are located in this Province. Small deposits of chrome are located some seven miles northeast of Holguin, on the slopes of a low ridge of serpentine that lies between two higher ridges of steeply inclined limestone, about a half mile distant from each other. One pocket had yielded about 150 tons of ore, which with 25 tons of float was ready for shipment in March, 1918. Analysis of samples showed an average of 34% of chromic oxide. The maximum content of chromium in pure chromite is 46.66% and the content of chromic oxide is 68%. Late in July of that year the company’s consulting engineer reported that a large body of 40% ore had been developed, and that in all about 500 tons were ready for shipment.
One of the larger deposits of chrome that gives promise of a considerable output is located on the south slope of the Sierra de Nipe, about seven miles southeast of Woodfred, the headquarters of the Spanish American Iron Company’s Mayari mines. The upper part of the ore body crops out of a steep hillside about 300 feet above a mountain stream, flowing into a small tributary of the Mayari River, and seems to be from ten to thirty feet in thickness. Where it does not crop out, it lies from 30 to 50 feet below the surface. The ore varies in quality, the better grade carrying as high as 48% of chromic oxide, with 7% to 15% of silica, and 7% to 10% of iron. The deposit was estimated to contain about 50,000 tons of chrome ore, 25,000 tons of which would carry more than 40% of chromic oxide and the remaining 25,000 tons between 34% and 40%.
The Cayojuan group of chrome ore claims are located on both sides of a small river emptying into Moa Bay, and lie at an altitude of about 750 feet above the sea level. An outcrop that extends around the hill for about 300 feet, and covers some 6,400 square feet, has been prospected. Samples on analysis gave an average of 38.1% chromic oxide.
The Narciso claim, which nearly surrounds the above group, includes an ore body that crops out on a steep hillside, about 500 feet above the river. A sample of ore from this outcrop showed an analysis of 34.8% of chromic oxide.
The Cromita claims, one the left side of the river, contain three known ore bodies, and hundreds of tons of boulder float ore, in an arroyo or gulch. The ore bodies are exposed on the side of a bluff at a height of 150 to 300 feet above the river. The most northerly ore body shows a face 20 feet wide and 15 feet high. The middle body includes an outcrop 75 feet long and 50 feet high and has been penetrated by cutting a tunnel. Geological conditions would indicate that these bodies are connected within the hill. Samples of these ores on analysis varied from 26% to 40.5% of chromic oxide.
The deposits of the Cayojuan group contain probably about 22,500 tons of available chrome ore, but may run as high as 60,000 tons. These estimates include 2,000 tons of float ore in the Cayojuan River and the tributary arroyo. The group of deposits is about eight miles by mule trail from an old wharf at Punta Gorda, to which a road will have to be built along the valley of the Cayojuan, a narrow gorge bordered in many places by steep cliffs. A light tramway for mule cars, or a narrow gauge steam railway, will probably be the most economical way of removing the ore.
The Potosi chrome claim is located on Saltadero Creek four miles above its mouth. This is a tributary of the Yamaniguey River. The ore body is a steeply dipping lens that reaches a depth of more than 100 feet and at one place has a thickness of 250 feet with a length along the strike, of 45 feet. The upper edge crops out about 325 feet above the creek bed, and about 600 feet above sea level. The ore is medium to coarse grained. Some of the material in the drifts is spotted but most of the outcropping and float ore is black and of good appearance. According to the analysis that accompanied the report of G. W. Maynard, the representative ore contains 35% to 41% chromic oxide. This deposit contains from 10,000 to 20,000 tons and the work of getting the ore to the coast involves rather a difficult problem in transportation.
A small body of chrome ore occurs on the Constancia claim, three-quarters of a mile south of Navas Bay, and about 100 feet above the sea level. The ore body appears to extend about 50 feet along the face of a gently sloping hill. It is not of a uniform quality, being largely a spotted ore; that is chromite mixed with serpentine ganue. About six feet of better ore, however, is exposed in a cut some 25 feet in length. This contains 39.4% chromic oxide. Water for concentration is available near by in the Navas River, and a road could easily be built to the bay, but this is not deep enough for steamers, so it would have to be lightered four miles north to Taco Bay, or ten miles southeast to Baracoa. Another body containing about 10,000 tons of chrome ore of low-grade lies in the mountain eight miles south of Navas Bay.