Early literature about the quarry offers several hypotheses as to the origin of the yellow color.
H. Newland, author of 1916 “The Quarry Materials of New York Granite, Gneiss, Trap and Marble,” published by the New York State Museum ascribed the color to the presence of a little limonite stain distributed along the borders and microscopic cracks of the quartz and feldspar, particularly of the quartz which appeared to carry most of the coloring matter.
In 1924, a researcher noted that there were actually two shades of the golden granite: a light buff found nearer the surface of the quarry and which changed very abruptly to a deeper shade. The lighter shade had much the same mineralogy as the darker shade but lacked the deep yellow quartz.
And in 1931, another researcher noted that when the yellow quartz grains were picked out from the granite after being crushed and boiled in acid, the color was entirely removed from them indicating that the color was only a surface effect and was not due to something dissolving in the quartz itself.