This firm was in business from at least 1865, and continued until 1889 when the business failed; they were succeeded by Cutter & Wood. Union Stone Co.'s primary product line consisted of artificial stone products, such as emery wheels, but they also made various types of grinders as well.

Ad from 1883 edition of "The Worcester Almanac, Directory and Business Advertiser"

Information Sources

• The report of the The Tenth Exhibition of the Massachusetts Charitable Mechanic Association, September, 1865, has this item:

  UNION STONE CO., Boston. Artificial Stone. By an entirely new process, this Company have succeeded in manufacturing emery wheels, hones, whetstones, grinding stones, imitations of soapstone, &c., that are remarkable for their strength and excellence. The composition of these articles has been examined, and for this new and useful application of material, your Committee recommend a Bronze Medal.

• The Official Catalogue of the Centennial Exhibition, 1876, lists this firm as an exhibitor of "Articles in artificial stone, soapstone register borders, millstone cement, etc. Emery wheels."
• Ad in Drew, Allis & Co.'s The Rochester Directory, 1878.
• Johnson's New Universal Cyclopedia, 1878, has an article on artificial stone that provides details on the artificial stone developed and patented by Frenchman Stanislas Sorel and used by Union Stone Co.
• Wilson's New York City Copartnership Directory for March, 1879, lists "Union Stone Co. (James L. Little, Pres.; George F. Clough, Sec. Capital, $150,000) 106 Liberty."
• The November 1882 issue of Manufacturer & Builder has an article about the Boston Fair that was then ongoing, including the following paragraph.

  The Union Stone Co., of Boston, exhibit a full line of their emery wheels and emery wheel machinery for grinding and polishing. Mr. John F. Wood, the treasurer of this company, is the able treasurer of the fair, to whom so much credit for its success belongs.

• The July 1883 issue of Manufacturer & Builder has an ad for the Third Annual Exhibition of the New England Manufacturers' & Mechanics' Institute, to be held that September 2 to November 3. "JOHN F. WOOD, Treas., 38 Hawley Street, Boston, Mass."
• Ad in Drew, Allis & Co.'s The Worcester Almanac, Directory and Business Advertiser, 1883. The 1880 edition also has an ad for them, but it was on the back cover, and the copy available through Google Books has been rebound so the ad is missing.
• The 1888 Railroad, Telegraph and Steamship Builders' Directory lists this firm as a maker of emery cloth, grinders, diamond tools, cement, and emery wheels.
• The November 1889 issue of Stone has a brief news item:

  The Union Stone Company of Boston, Mass., recently informed its creditors that its liabilities were $64,806, of which $16,500 is secured assets, nominally, $98,000. The general feeling is that all creditors will be paid in full. Two additional assignees were chosen.

• The Jewelers' Circular and Horological Review for 1891 had this snippet:

  Mr. Hyde started in business in February, 1890. Prior to that time he represented the Union Stone Co., of Boston, as their manager in New York, and when the assigned he acted as assignee for a time and eventually bought the balance of their stock here. Most of his stock consisted of consigned goods.