Rocks and Minerals

  The rocks and minerals described in this booklet can be found in Maine. Some are very plentiful while others are hard to find. Chebeague Island's K-3 graders have been studying rocks and minerals this year and decided it would be nice to have their own Maine Rocks and Minerals Book. They have utilized a collection and information put together by the Maine Geological Survey. A number of the children from the class, along with Beverly Johnson and geologist Carol White got together, took pictures and wrote up descriptions of the collection for this booklet.

Click on the picture to see more
pictures from the classroom.

Important Terms
Mineral: a natural solid substance of a definite chemical composition and crystalline structure
Rock: a mixture of one or more minerals
Three classes of rocks:
Igneous: Rocks formed when hot, melted rock deep in the earth cools and becomes solid.
Sedimentary: Fragments of shells, stones or plants that accumulate on the bottom of lakes; rivers or seas are called sedimentary. Over time the layers of sediment squeeze together until they stick together to form solid rock.
Metamorphic: Metamorphic rock forms when sedimentary, igneous or other metamorphic rock is heated or squeezed.
Luster: the degree of shininess of a mineral

 Can you name the minerals below?






















 Chert (Ledge Ridge,Parmachanee Township)

Chert is a sedimentary rock composed predominantly of silica. Maine chert has been used by paleo-indians and native Americans for arrowheads and tools.


 Basalt (Casco)

Basalt is a dark, fine grained volcanic rock that is formed when magma is extruded near or at the earth's surface. Basalt is composed of feldspars and iron-rich pyroxene minerals.


 Mica Schist (Windham)

Mica schist is a metamorphic rock with a distinct platy layering. This rock is composed of white & black mica and pink garnet.


 Andesite (Raymond)
Andesite is a fine-grained igneous rock that is generally gray to greenish gray in color. Andesite is made up of feldspars and quartz.


 Serpentinite (Deer Isle)
This dark green metamorphic rock is composed of serpentine, an iron-rich mineral with a waxy luster.


 Gneiss (Woolwich)
This banded metamorphic rock is composed of alternating bands of light minerals - quartz and feldspar and dark minerals - iron-rich, black hornblende and mica.


 Granite (Ellsworth)
This granite is an igneous rock composed of the minerals quartz, feldspar and mica. Granite was and continues to be an important commercial rock in Maine for buildings and homes.


 Marble (Union)
This rock, originally limestone, was metamorphosed by intense heat and pressure to form marble. Maine marble is used primarily in the production of cement and agricultural lime. Marble is made of calcite, dolomite and metamorphic minerals.


 Granite (Minot)
This coarse-textured granite is called a pegmatite. It is composed of quartz, feldspar, mica and tourmaline minerals. Pegmatites are a source of many gemstones in Maine.


 Conglomerate Pennsylvania
This sedimentary rock is made up of rounded pebbles of quartz that have been cemented together by crystallized sand and mud.


 Tuff (Enchanted Stream, West Forks)
This volcanic rock is comprised of volcanic ash, volcanic rock fragments, and consists primarily of silica.


 Black Slate (Monson)
This rock is a dark, fine-grained metamorphic rock that was originally a shale or a mudstone. Slate has a characteristic "slaty" or platy cleavage. Slate is still quaried for building and decorative stone. Black slate has microscopic pieces of mica and quartz.


 Rhyolite (Mount Kineo)
This very fine grained igneous rock is similar in composition to granite, but the crystals are extremely small. It is made up of feldspar and quartz minerals.


 Limestone (St Agatha)
This sedimentary rock from Northern Maine is composed of a mixture of corals, limy sand and mud. It is made up of calcite.


 Gray Sandstone (Waterville)
This fine grained metamorphosed sandstone is composed of feldspar, quartz and volcanic minerals.


 Red Sandstone (Great Pond)
This sedimentary rock is made up of feldspar, quartz, and rock fragments. The red color is due to the limonite iron oxides present in the rock.


 Amphibolite (Richmond)
This dark, fine-grained rock is a metamorphosed basalt. It is made up of amphibole minerals such as hornblende, as well as feldspars and quartz.


 Gabbro (Wayne)
This coarse-grained igneous rock is composed of feldspar and dark minerals of either hornblende or pyroxene.


 Quartzite (Wyman Lake)
This metamorphic rock is made up of primarily silica minerals such as quartz.


 Fossiliferrous Sandstone (The Forks)
This sedimentary rock contains fossilized shells cemented together by silica. It is made up of calcite, dolomite and aragonite minerals.



 1 - Spodumene (Newry)
A lithium aluminum silicate that is generally off-white to pale green to pale violet in color. It is often found in pegmatites.


 2 - Lepidolite (Newry)
A fine-grained mica that contains small amounts of lithium which gives it a characteristic purple color.


 3 - Tremolite (Rockland)
A yellow, green, or off-white mineral of the amphibole family.


 4 - Galena (Lubec)
A lead sulphide mineral which forms cubic silver gray metallic crystals


 5 - Microcline feldspar (Topsham)
A potassium, aluminum silicate mineral that is usually off-white to pink to tan in color. A common mineral in granite.


 6 - Pyrite (Gilead)
An iron sulfide mineral with brassy color metallic cubic crystals. Often called "fools gold." A common mineral in metamorphic rocks in Maine.


 7 - Chalcopyrite (Harborside, Brooksville)
A copper-iron sulphide mineral with a gold metallic luster. This mineral is an important ore of copper.


 8 - Sphalerite (Harborside, Brooksville)
A zinc-iron sulphide mineral that is usually brown or black in color. This is a zinc ore that was mined in Maine.


 9 - Apatite (Buckfield)
A calcium phosphate mineral with glassy luster that is found in pegmatites in Maine.


 10 - Grossular Garnet (Minot)
A reddish-brown, calcium - aluminum silicate mineral commonly found in metamorphic rocks.


 11 - Clear/milky Quartz (Albany)
A silicon dioxide mineral with a glassy luster. Quartz is found in igneous, metamorphic and volcanic rocks in Maine.


 12 - Smoky Quartz
This variety of quartz has a smoky gray to black color.


 13 - Muscovite (Paris Hill)
A potassium, aluminum silicate mineral with a characteristic silvery color and platy cleavage. Muscovite is a common mineral in granites and metamorphic phyllites and gneisses.


 14 - Biotite (Peru)
A black iron aluminum silicate mica mineral found in granites, schists, phyllites & gneisses.


 15 - Tourmaline (Georgetown)
A silicate of aluminum, boron & other metals, tourmaline is formed in pegmatites throughout the State. It has a characteristic pencil like shape with parallel ridges on the crystal surface. Tourmaline is the Maine State gemstone.


 16 - Staurolite (Windham)
A brown to black iron aluminum silicate mineral often found in metamorphic rocks. Sometimes forms cross-shaped crystals or "fairy crosses."


 17 - Limonite (Katadin Iron Works, Brownville)
A light brown to rusty colored iron oxide mineral.

 18 - Chlorite (Newry)
A blackish green magnesium and iron aluminum silicate found in metamorphic rocks in Maine.


 19 - Almadine Garnet (Peru)
A dark red to brownish red to black iron-aluminum garnet that forms crystals. It is found in igneous & metamorphic rocks.


 20 - Beryl (Buckfield)
A beryllium aluminum silicate mineral with characteristic hexagonal crystals. Beryl is found in Maine pigmatites in many colors.