gbrnorts_001. Gabbronorite from the Stillwater Igneous Complex, Montana, in the basal zone from the ridge above the Benbow Mine. Pale tan and pale green pyroxenes with colorless interstitial plagioclase feldspar. Smith College Collection (SIC-3).

gbrnorts_002. Thin section of gabbronorite in plane polarized light. Orthopyroxene and augite with interstitial plagioclase feldspar. Sample from the Bushveld Igneous Complex, South Africa. Approximate height in layered sequence 6010 meters. Mark Brandriss Collection, Smith College (BV-107).

gbrnorts_003. Thin section of gabbronorite in plane polarized light. Augite and rounded grains of orthopyroxene surrounded by plagioclase feldspar. Sample from the Bushveld Igneous Complex, South Africa. Approximate height in layered sequence 6090 meters. Mark Brandriss Collection, Smith College (BV-204).

gbrnorts_004. Thin section of gabbronorite in plane polarized light. Orthopyroxene and augite surrounded by plagioclase feldspar. Sample from the Bushveld Igneous Complex, South Africa. Approximate height in layered sequence 6550 meters. Mark Brandriss Collection, Smith College (BV-202).

gbrnor_005. Norite thin section from the Bushveld Igneous Complex, South Africa - Mark Brandriss Collection, Smith College (BV-203). Approximate height in layered sequence is part of the "Marginal Zone". Mark Brandriss Collection, Smith College (BV-203).

gbrnor_006. Plagioclase-rich gabbronorite from the Stillwater Igneous Complex, Montana. Dark brown enstatite and black clinopyroxene with grayish white interstitial plagioclase feldspar. Smith College Collection (SIC-12).

gbrnor_007. Gabbronorite thin section from the Bushveld Igneous Complex, South Africa - Mark Brandriss Collection, Smith College (BV-014). Orthopyroxene and augite surrounded by grayish white plagioclase feldspar. Approximate height in layered sequence is 5600 meters.