Some of the best places to find “Herkimer diamonds” today are located along New York State Routes 28 and 29 near Middleville, New York. (When visiting this area it is important to remember that all land in New York either belongs to the government or is private property. Collecting minerals from government lands is illegal in New York, and collecting on private property always requires permission in advance. Learn more about the laws governing mineral collecting in the United States.)

There are several commercial mines on New York State Routes 28 and 29. These include Ace of Diamonds Mine, Herkimer Diamond Mines, and Crystal Grove Diamond Mine and Campground. These mines allow collectors to enter and prospect for a nominal fee. They also rent equipment such as rock hammers, wedges, and other small tools. They also have small exhibit areas where you can view and/or purchase specimens.