1860 Clark, Gruber & Company $10 Copper Die Trial NGC Proof-63 Brown. K-3. The design shows a triangular-shaped mountain meant to represent Pike’s Peak. However, the Philadelphia die sinker had never seen the mountain or a representation of it, thus when the trials were shipped westward they were immediately rejected. The surfaces are glossy, dark brown with bright, gleaming fields on each side. This is possibly one of three to four examples ever struck, quite possibly for dignitaries, and is seldom encountered for sale today. The surfaces have a glossy reflective appearance typical of a proof coin for this era.