MUSCOVITE PHYLLITE. KAl 2 (AlSi 3 O 10 )(F,OH) 2. Metamorphic. Crystal System: Monoclinic Hardness: Cleavage: Perfect on [001]

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1 0001 MUSCOVITE KAl 2 (AlSi 3 O 10 )(F,OH) 2 Phyllosilicate Crystal System: Monoclinic Hardness: Vitreous Cleavage: Perfect on [001] Associated with the pegmatite at Tamminen Quarry, Oxford, ME (D1). An incredibly common mineral, muscovite forms familiar sheets of mica found in igneous and metamorphic rocks. A burdened geologist carrying bags of specimens through the pegmatite quarry where this specimen was collected. Photo: Gemma Venuti N, W 0002 PHYLLITE Metamorphic Waterville Formation, ME (Sw) (Silurian) Waterville, ME Fine-grained micaceous phyllite. Fissile, foliated when held along thin portion. Principle minerals chlorite, muscovite, and pyrite. Phyllite is slightly between slate and schist on the metamorphic scale. It began as a sedimentary rock, but was then subjected to pressure and heat, allowing crystals of mica to grow to a larger size than slate. A stealthy geologist evaluates the bedrock before mining a sample. Photo: Sarah Hall N, W

2 0003 QUARTZ SiO 2 Tectosilicate Crystal System: Hexagonal Hardness: 7 Vitreous, greasy Cleavage: (Fracture) Associated with the pegmatite at Tamminen Quarry, Oxford, ME (D1). Perhaps the most common mineral in the world, quartz is found almost ubiquitously in pegmatites as shown here. A triumphant geologist stands above the tailings pile where this specimen was collected. Photo: Matt Messina N, W 0004 SILTSTONE Sedimentary Rocky Harbor Formation, NL (Neoproterozoic) Bonavista, NL Silicious grey-green siltstone with slight metamorphism. Fissile, weathering into ocean. This siltstone was deposited in a low-energy ocean between million years ago. It is poorly sorted, but contains particles of silicious debris. Its density is owed to the slight metamorphism undergone by this formation. This specimen has been altered on three faces. View of outcrop showing the fissile nature of this particular bedrock. Photo: Matt Messina N, W

3 0005 MOLYBDENITE MoS 2 Sulfide Crystal System: Hexagonal Hardness: 1-2 Metallic, vitreous Cleavage: Perfect on [0001] Associated with the Catherine Mountain granite (D1) in Sullivan, ME. An outcrop at the abandoned prospect where this specimen was collected. Photo: Spencer Gray N, W 0006 LEPIDOLITE K(Li,Al) 3 (Al,Si,Rb) 4 O 10 (F,OH) 2 Phyllosilicate Crystal System: Monoclinic Hardness: Sub-vitreous, pearly Cleavage: Perfect on [0001] Associated with the pegmatite at the Havey- Berry Quarry, Poland ME. A view of the tourmaline, lepidolite and plagioclase crystals at the Havey-Berry Quarry, Poland, ME. Photo: Duncan Pay

4 0007 MARBLE Metamorphic Penobscot Formation (Oεp) (Ordovician-Cambrian) Rockport, ME Fine-grained metamorphosed limestone, highly weathered. Maintains semi-fissile nature. Associated with calcite, dolomite. Highly sought after for architectural design and sculpture purposes, marble is a metamorphic rock whose protolith, limestone, was formed by the calcareous tests of marine zooplankton such as formaniferans and coccolithophores. A geologist points out the outcrop from where this specimen was collected. Photo: Sarah Hall N, W 0008 HORNFELS Metamorphic Bucksport Formation, ME (Devonian-Ordovician) Dedham, ME Banded, small grained rock with irregular to conchoidal fracture. Deep red-brown, banded. Principle mineral quartz, muscovite. Hornfels" is a general name given to rocks in which a sedimentary protolith was heated and metamorphosed by a nearby magma chamber. While hornfels often maintain the banded pattern of their parent rock, it does not break along planes of weakness. This specimen most likely formed as the result of contact metamorphism from the nearby Lucerne magma chamber. The Dedham Quarry in Dedham, ME, from which this specimen was collected. Photo: Matt Messina N, W

5 0009 SCHORL NaFe 2+ 3Al 6 (BO 3 ) 3 Si 6 O 18 (OH) 4 Cyclosilicate Crystal System: Trigonal Hardness: Vitreous, resinous Cleavage: Fracture Associated with the pegmatite at the Havey- Berry Quarry, Poland ME. Blasted rocks from the pegmatite mine reveal large chunks of schorl tourmaline. Photo: Gemma Venuti 0010 Pegmatite (D1) intruding Sangerville Formation, ME (Sspm) (Devonian) Poland, ME PEGMATITE Igneous A pegmatitic granite with typical felsic composition. Associated minerals quartz, muscovite, microcline feldspar and tourmaline, var. elbaite. Igneous pegmatites are often associated with slow-cooling magma chambers which allow minerals to grow large. The site where this specimen came from is an active mine where gem-quality tourmaline is found. Pieces of loose pegmatite are found commonly in the tailings pile at the Havey-Berry mine. Photo: Gemma Venuti

6 0011 FOSSILIFEROUS SANDSTONE Sedimentary Oread Limestone Formation, KS (Pd) (Pennsylvanian) Lawrence, KS Medium-grain limey sandstone, poorly sorted with fossilized echinoderms (Crinoidea). Principle mineral calcite. Roughly 300 million years ago, the portion of crust that is now the state of Kansas was close to the equator and submerged under a prehistoric Ocean. The calcareous tests of dead marine organisms then settled in an ooze on the ocean floor, cementing into the rock we see today. The roadside talus pile where this specimen was collected. Photo: Google Earth N, W 0012 URANINITE UO 2 Oxide Crystal System: Isometric Hardness: 5-6 Metallic, vitreous, dull Cleavage: Fracture Associated with the pegmatite at the Havey- Berry Quarry, Poland ME. Excited students unwittingly mine into the active uranium site where this specimen was collected. Photo: Sarah Hall

7 0013 PHANERITIC GRANITE Igneous Cadillac Mountain Formation, ME (D1) (Devonian) Winter Harbor, ME Famous Cadillac Mountain granite is phaneritic in texture. Associated minerals quartz, microcline feldspar and hornblende. The magma chamber that makes up a large portion of Mount Desert Island can also be found on parts of Schoodic peninsula, such as this road-cut in Winter Harbor. The rocks here are almost identical in their pink color and similar crystal sizes. The roadside outcrop where this specimen was collected. Photo: Matt Messina 0014 GRAPHIC GRANITE Igneous Pegmatite (D1) intruding Sangerville Formation, ME (Sspm) (Devonian) Poland, ME Graphic granite is a common name for the repeating patterns of quartz and microcline feldspar displayed in felsic pegmatites. Its formation has been the cause of debate for decades. A hopeful geologist examines the rocks at the Havey-Berry mine, hoping to get as nice a sample of graphic granite as this. Photo: Gemma Venuti

8 0015 MICROCLINE KAlSi 3 O 8 Tectosilicate (Feldspar) Crystal System: Triclinic Hardness: 6 Earthy, vitreous Cleavage: Imperfect on [001], [010] Associated with the pegmatite at Tamminen Quarry, Oxford, ME (D1). A tentative geologist examines a sample of plagioclase at the Tamminen quarry in Oxford, ME. Photo: Sarah Hall N, W