Fact #1 The minerals industry in Minnesota is about as large as the agriculture industry. Taconite production alone creates nearly $2.5 Billion gross product value.

Fact #2 Sedimentary Stone is made from the mineral calcite, which came from the beds of evaporated seas and lakes, and from sea animal shells. Limestone is one of the most widely recognized sedimentary stones.

Fact #3 Metamorphic Stone has changed from one type of stone to another. Marble is the most common metamorphic stone. It is made primarily of calcium carbonate, and has been crystallized by exposure to heat and pressure.

Fact #4 Igneous Rock is formed from a molten mass that has cooled over millions of years below the earth's surface. Igneous rocks include granite and granite-like materials such as basalts and gabbros.

Fact #5 Igneous Rock (granite) is very dense and hard. It is third in hardness to diamonds and other precious stones like rubies and sapphires.

Fact #6 Molten rock below the earth's surface is called magma. Molten rock above the earth's surface is called lava

Fact #7 Morton Gneiss (guh-nice) is one of the oldest kinds of rock on Earth and probably the oldest type of rock in the USA. It's about 3.5 billion years old, and is found in various places along the Minnesota River. Very large flat slabs of it are mounted on the front of the Qwest office building on Kellogg Boulevard, the Ramsey county office building on Plato Boulevard, near St Peters Street, and on other building walls in downtown Saint Paul. ??

Fact #8 One of the best places in the USA to find Ordovician fossils (approximately 450 million years old) is across the Mississippi from downtown Saint Paul in the Lilydale Regional Park.

Fact #9 The brilliant white dome and upper walls of the Minnesota state capitol are made of marble from Georgia. The architect, Cass Gilbert, who was 35 years old at the time, and raised in St Paul, insisted that the capitol would be far more impressive if it were light colored. No rock from Minnesota would suit this requirement. ?Gilbert did call for Minnesota-quarried sandstone and granite for the building's lower levels, the steps, and terraces, and for local Kasota stone for much of the interior.

Fact #10 The rock quartzite, one of the stones being used by the sculptors at the symposium, normally looks reddish violet, but is the origin of the name for "Blue Mound State Park" in the southwestern corner of Minnesota. Apparently early European settlers thought the beds of quartzite they saw looked blue in certain light. Near Luverne Minnesota there are very noticeable hills or mounds of quartzite, which came to be called the "Blue Mounds".

Fact # 11 Morton Gneiss (guh-nice) is one of the oldest kinds of rock on Earth and probably the oldest type of rock in the USA. It's about 3.5 billion years old, and is found in various places along the Minnesota River. Very large flat slabs of it are mounted on the front of the Qwest office building on Kellogg Boulevard, the Ramsey county office building on Plato Boulevard, near St Peters Street, and on other building walls in downtown Saint Paul.   

Fact #12 One of the best places in the USA to find Ordovician fossils (approximately 450 million years old) is across the Mississippi from downtown Saint Paul in the Lilydale Regional Park.

Fact #13 The brilliant white dome and upper walls of the Minnesota state capitol are made of marble from Georgia. The architect, Cass Gilbert, who was 35 years old at the time, and raised in St Paul, insisted that the capitol would be far more impressive if it were light colored. No rock from Minnesota would suit this requirement.  Gilbert did call for Minnesota-quarried sandstone and granite for the building's lower levels, the steps, and terraces, and for local Kasota stone for much of the interior.

Fact #14 The rock quartzite, one of the stones being used by the sculptors at the symposium, normally looks reddish violet, but is the origin of the name for "Blue Mound State Park" in the southwestern corner of Minnesota. Apparently early European settlers thought the beds of quartzite they saw looked blue in certain light. Near Luverne Minnesota there are very noticeable hills or mounds of quartzite, which came to be called the "Blue Mounds".  

Fact #15 The exterior of the St Paul Public Library (completed in 1917 and located on Rice Park in downtown Saint Paul) is of white Tennessee Marble. The interior is finished in gray Mankato stone.

Fact #16 The exterior of the St Paul Cathedral is of Rockville granite from the Saint Cloud area, while the interior is constructed of American Travertine from the Mankato area. Cathedral. Construction began in 1906, and the building   opened in 1915.

•  The Basilica of St Mary in Minneapolis is constructed of "Bethel white" granite from Vermont, and other granite from quarries in Minnesota. Groundbreaking was in 1907, and the first mass was held in 1914, although the interior was not completed until 1926.

Fact #17 Magma can be divided into two principle types. 1) Basaltic , which contain around 50 % silicate material (SiO2) and 2) Granitic which have 60 to 75 % SiO2.   Basaltic have temperatures from 900 to 1200 degrees C (1600 to 2200 degrees F) and Granitics have temps usually lower than 1500 degrees F.

Fact #18 Magma is often a combination of solids, liquids and gases.   It may be more correct to think of it as slush than a simple liquid.   Gases are often dissolved, like carbonation in a soda pop.   When the overburden pressure is released, the gases come out of solution, the way soda pop "foams" when the bottle is opened.   The igneous rocks of the Minnesota North Shore have many holes, which were formed by these gases coming out of solution.   Over time, the holes may fill with minerals, creating the beautiful Lake Superior Agates.

Fact #19 Igneous rocks have something referred to as texture.   The size of the crystals in the rock gives the texture.   Lava which is quenched into water, have no crystals, giving a glassy texture (example: obsidian ).   The atoms in that type of rock cooled so quickly they did not have time to organize into crystals.

Fact #20 Molten material that came onto the surface or near surface will cool rapidly and form micro-crystals, crystals that can only be seen with very powerful microscopes.   These are called aphanitic (Greek:   " a " meaning "not" and " phanitic " meaning "visible").   Anyone in Minnesota with a rock garden has seen the uninteresting gray and frequently well-rounded rocks with no crystal structure.   These are examples of aphanitic rocks.