Ruby Nill (previous name Archimedes) is a Carlin-style sediment-hosted gold deposit in carbonate rocks. The ore is a mixture of jasperoid and decalcified limestone exhibiting strong structural controls. Micron-size gold is associated with oxidized pyrite sites and is strongly fracture controlled. Deeper portions of the east Archimedes resource are sulfidic, and root-zones include retrograde-altered base metal skarn and marble hosts. The mineralized area closely adjoins a Cretaceous porphyry intrusive and may be genetically linked to it, as both base metal-related adularia and the intrusive yield similar radiometric ages. Some evidence suggests the presence of a younger cross-cutting Au-As-Hg system superimposed on the earlier base-metal system and associated with Oligocene magmatism. The West Archimedes deposit is about 780 m long, plunging gently S60?E and covered by 15 to 150 m of partially cemented calcareous alluvium. The deposit is subtabular to ovate in cross section, branching locally at structural intersections. The orebody has a central elongated lens of higher grade jasperoid ore enclosed by a more tabular envelope of lower grade decalcified limestone ore.

The West Archimedes deposit of the Ruby Hill Gold Mine is developed by an open pit in an area previously mined for polymetallic deposits by underground methods. A mill, haul roads, leach pads, and waste dumps are also present on the property.

The Ruby Hill operation consists of an open pit mine, two waste rock facilities, a two-stage crushing system, a ball mill (inactive), thickener (inactive), belt filters (inactive), ore conveying and stacking system, a multi-cell heap leach facility, a pregnant solution tank and overflow pond, two storm water ponds, an Adsorption-Desorption-Recovery (ADR) Plant, a precious metals
refinery, associated interconnected pipelines, and support buildings.