An example of Queen Anne architecture as expressed in a commercial setting, the Diamond Block is one of only four buildings of this style in the district. Three stories in height, the building has two story oriel windows the full length of the façade, interrupted by balconies over an arched entrance. Built entirely of cut stone, its embellishments consist of periodic pilasters and a double row of corbeled stone dentils at the cornice.
Forced into the shape of a triangle by the less than stringent layout of streets, Sixth Avenue and Last Chance Gulch (yes, that's a street name) in particular, the two rear sides of the building are plain, unadorned brick and stone. An interesting aspect of the building is the false front at the west end of the façade. In order to not break up the continuity of the façade because of the lack of building behind the west end, it becomes a false front behind the final two oriel windows.
Diamond Block
Name Address Style Date Status
Diamond Block 40-52 W. 6th Queen Anne Comm. 1889 Primary
19 - Diamond Block (Mark Meloy, 1989)
The Diamond Block, located near the center of Helena's present-day commercial district, was one of five buildings developed by Montana's "merchant-prince", T. C. Power. Designed by James Stranahan, the building's plan conforms to the triangular mining claim on which it was built. The
asymmetrical design and unusual detailing on the building reflect the skill of the architect.
From the NRHP Registration Form
This building is the first real departure from the more formal architecture of the Richardsonian era and the Chicago School. The unequal spacing of the bays, the arrangement of entrance pilasters, the small balconies, the copper faced bay windows, the three centered arches and the careful handling of the stone cornice and stone grillwork at the principal entrance all show some originality of composition. Louis Sullivan may have coined the phrase that "form follows function" and here the principal entrance to this triangle shaped plan is offset to, one side as the floor
space requires. The secondary entrance is smaller as fits its importance and located at its proper place on the triangle. The widest window bay which does not match the others, is at the apex and was made necessary because the end rooms had to be much longer than the others because of the triangle shape.
The addition of decorative copper work and the tiny sparkling faceted mirrors make this façade a very interesting composition in stone, glass, copper and wrought iron that certainly deserves a place on the list of buildings that show the architectural history of Helena.
From the NRHP Registration Form