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�00 <br /> "TWINING <br /> CONCRETE INSIGHT <br /> Morrison Quarry Rock Petrography Page 27 <br /> 4.4 Rock Sample HDR-003 (53.0-53.6): Biotite Gneiss <br /> Received Condition <br /> The sample is a rock fragment that measures —60 mm (2 % in.) in diameter and <br /> —190-202 mm (7 '/2 - 8 in.) in length (Figure 4.4a). Both ends of the core are fractured <br /> surfaces and the side surfaces are rough cored surfaces. The core was received intact in one <br /> piece. No weathered surfaces are present. <br /> Polished Slab <br /> The rock on the polished surface is off-white to reddish-gray and reddish brown (Munsell <br /> Soil Color 2.5YR 6-8/1 and 4-5/3) and predominantly consists of quartz, orthoclase feldspar, <br /> plagioclase feldspar, biotite, with minor amounts of calcite and talc, and trace amounts of <br /> pyrite (Figure 4.4b, Figure 4.4c). The rock sample exhibits a well developed gneissose <br /> structure with alternating felsic (quartz, feldspar) and darker mineral layers (biotite). Gneissic <br /> layers measure up to —25 mm (1 in.) thick and are laterally continuous. Quartz and feldspar <br /> grains are medium grained and measure up to —1 mm (40 mil) in diameter. The rock sample <br /> exhibits a few randomly oriented veins filled with calcite, talc, and feldspar. Trace amounts <br /> of pyrite is observed causing a reddish-brown staining/discoloration. The majority of the rock <br /> sample is hard and competent, and exhibits a Mohs hardness of 3-4+. A few talc-rich areas <br /> exhibit a Mohs hardness of<2. <br /> Thin Section <br /> The rock is a high-grade metamorphic rock classified as a biotite gneiss (Figure 4.4d, <br /> Figure 4.4e, Figure 4AS, Figure 4.4.g). The sample consists of major amounts (>10%) of <br /> fine to medium grained quartz, orthoclase feldspar, plagioclase feldspar, and biotite <br /> measuring up to —1 mm (40 mil) in diameter. A trace amount (<1%) of opaque minerals are <br /> observed. Quartz and felspar grains are subhedral to anhedral in shape and occur as <br /> segregated layers. Biotite grains are elongated in shape and exhibit a preferred orientation. <br /> Calcite and talc predominately occur in randomly oriented veins throughout the sample. <br /> Sample HDR-003(53.0-53.6): Biotite Gneiss A Is <br /> Major minerals Quartz(-50-60%),feldspar(-20-30%),biotite(-20-30%) <br /> (10-100%by volume of rock) <br /> Minor minerals Calcite(-1-5%),talc(-1-5%) <br /> (1-10%by volume of rock) <br /> Trace minerals Pyrite,opaque minerals <br /> (<1%by volume of rock) <br /> Report No. 227893.d 22 November 2022 <br />