Two-circle Contact Goniometer
Geology, Mineralogy and Crystallography
<strong>Physical Description:<br /></strong> <br />The two-circle contact goniometer has a tripod brass base painted black. A small brass graduated disc is connected to the center of the base on a pedestal, and the center of this disc is allowed to rotate. A small pedestal is raised from the center of this disc for the placement of the mineral. A second large brass graduated circle runs perpendicular to the disc so that it arches over the disc and is connected to the tripod base on either end. A brass contact bar runs perpendicular to the large circle. One end of the contact bar sticks above the circle and has a knob, while the other end of the contact bar is near the center of the circle and bears a flat edge. A contact bar is bolted to a brass piece that surrounds the circle, leaving the graduated side visible.
<strong><br />Functional Description:<br /></strong>
<p dir="ltr"><span>To set up the two-circle contact goniometer, a crystal is placed on the specimen holder such that one crystal face is parallel to the graduated disk (also called the stage). The crystal face that is fixed to the specimen holder is selected based on the axis of a prominent zone. All measurements are taken in relation to this zone. Next, the contact bar is then positioned such that its end is parallel to and in contact with a second crystal face. The goniometer is used to find an intersection point between pairs of crystal faces. An intersection point can be visualized as a point which connects two perpendicular lines drawn from the two crystal faces. The intersection point is written as coordinates: one measured on the stage and one on the vertical circle. The stage has a range from 0 to 360 degrees. The vertical circle measures from 0 to 110 degrees. The coordinates can also be thought of as a polar distance and azimuth which are then plotted on a projection. Once all the intersection points have been determined and plotted, trigonometry is used to calculate the interfacial angles and indices. </span></p>
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Kelvyn Van Laarhoven, Stephanie Peterson, Kathryn Wells, Matthew Champion and Audri Mills
c. 1890-1910
English
Physical Object
UW38A106 P.STOE | HEIDELBERG | GERMANY
United States Of America, Germany
Crookes tube (X-ray generator)
Mineralogy; Physics; X-ray research
Physical Description: The body of the Crookes tube instrument consists of a copper cube, in the center of a metal stand. The stand consists of a long tube with three legs protruding from the base. There are two additional tubes that extend beyond the cube's surface. When looking at the instrument from the front, extending to the right is a glass cylinder that has copper tube extending the length of it on the inside. Less than halfway down the copper tube inside the glass cylinder is a metal ring that has holes along its circumference. Adjacent to the glass tube, pointing towards the viewer when looking at the instrument from the
front, is a metal tube. On the upper half of the instrument above the cube, there is a metal tube that narrows in diameter towards its top. The are several places that rubber vacuum tubes would attach to create a vacuum, two at the end of the glass cylinder, two at the end of the tube protruding from the top, and one directly attached to the main cube.
Functional Description: To operate the Crookes tube a voltage is applied between the metal electrodes at either end of the glass tube. The electric field produced by the application of a voltage causes the gas particles in the tube to accelerate and collide with other gas molecules. If the energy of the collision is high enough an electron will be forced off the gas molecule and a positive ion will form. This process of ionization will continue to occur as a chain reaction until most of the gas molecules in the tube have been ionized. The positive ions are then attracted to the negative cathode, and when the ions collide with the metal the electrons are removed from the surface. The voltage being applied to the tube causes the electrons to accelerate as they all move towards the positively charged anode at the other end of the tube. Due to the increased speed the electrons collide with the wall behind the anode which causes them to become excited. As the electrons become excited and return to their original energy level, x-rays are produced. The x-rays will then exit through the opening at the end of the metal tube which sits perpendicular to the glass tube. A sample can then be placed a certain distance away from the opening and when the x-rays hit the sample an image will be produced on a screen behind the sample.
Nicole Bliven, Shelby McGuire, Zach Nelson, Joseph Aldape, and Will Christian
c. 1940-1950
English
Physical object
United States of America
Agate Mortar and Pestle (1/3)
Geology, Mineralogy and Crystallography
<strong>Physical Description</strong><br />There are three unique agate mortar and pestles at A.E. Seaman Mineral Museum. The largest mortar measures three centimeters in diameter at the base, while the matching pestle measures five centimeters in length. This mortar and pestle set is a light brown color with translucent areas. The pestle is lighter than the mortar. Both are cut from agate, which gives the set a marbled and inconsistent color pattern. The mortar is a rounded bowl on the inside, but the outside edges form an octagonal shape. Each end of the pestle is rounded; one end of the pestle is smaller in diameter than the other by four and one half centimeters. <br /><br /><strong>Functional Description</strong> <br />The mortar and pestle has been used in laboratories for centuries for grinding and crushing various substances. This mortar and pestle is still in use for grinding powders for X-Ray diffraction. The mortar is shaped like a bowl in order to hold a certain amount of the substance to be ground. The pestle is then used to mash and grind the substance in the bowl until the desired consistency is reached. The agate mortar and pestle is used in circumstances where cross contamination must be avoided. This is because agate is one of the finest, most non-porous natural materials available for a grinding surface. Bacteria, contaminants, and other particles cannot penetrate the material.
Savannah de Luca
unknown
n/a
Physical object
none
Microscope Slides in Box
Geology, Mineralogy and Crystallography
<h2>Physical Description</h2>
These microscope slides are contained in a lightly colored oak box, featuring thin cuts of wood and brass hardware. The locking mechanism on the front of the box is made up of two rotating hooks on each side, located near the top of the box, and two open loops, located near the bottom of the box. The top of the box reads, in hand-written black ink, “Other Common Rock Forming/Minerals.” The box opens up to reveal 282 glass microscope slides and 18 empty slots for missing slides. Each slide is made of a mineral sample pressed onto a cut of glass. Each slide has two labels attached to the glass; on one of the labels, a typed font displays the words: “MICHIGAN MINING SCHOOL. NO.” and features a number unique to each mineral sample. On the other label, a name, number, and location of each mineral sample is hand-written in black ink. <br /><h2>Functional Description</h2>
The glass slides contains a mineral to be examined at a microscopic level. Slides were used to press thin strips of minerals flat and hold them easily for examination. The slide containing the mineral was placed and secured, and then the microscope is adjusted for viewing.
Savannah de Luca
c. 1880
English
Physical object
DM 31417
Wooden Crystal Models - Tetragonal
Geology, Mineralogy and Crystallography
<h2>Physical Description</h2>
These crystal models are composed of light pearwood. Each model is precisely shaped with correct facets and angles to illustrate seven different groups of crystal structures: isometric, tetragonal, hexagonal, orthorhombic, monoclinic, triclinic/trigonal, and twins. Some have been carefully sanded to represent natural curvature of face edges. Each individual model is unique, the length varying from 3 to 7 centimeters and the width from 2 to 7 centimeters. Some have identification numbers carved into them, which pertain to their original kit number given by the manufacturer. Some have handwritten numbers in black ink on their flat faces, which identify the name of the crystal they represent.<br /><h2>Functional Description</h2>
These crystal models were made as a tool for teaching crystallography and the morphology of crystals. Each model has unique external symmetry that replicates the actual crystal, providing a hands-on teaching practice that is still used today in class rooms. This specific collection is still used to teach crystallography at Michigan Technological University.
Savannah de Luca
c. 1910
English
Physical object
none
Wooden Crystal Models - Triclinic/Trigonal unpaired
Geology, Mineralogy and Crystallography
<h2>Physical Description</h2>
These crystal models are composed of a lightly colored Pearwood. Each model is precisely shaped with correct angles to illustrate various examples of seven different groups of crystal structures: isometric, tetragonal, hexagonal, orthorhombic, monoclinic, triclinic/trigonal, and twins. Some have been carefully sanded to represent natural curvature of face edges. Because each individual model is unique, the length varies from 3 to 7 centimeters, the width varies from 2 to 7 centimeters, and each has a unique weight. Some have identification numbers carved into them, which pertains to their original kit number given by the manufacturer. Some have hand written numbers in black ink on their flat faces, which identify the name of the crystal they represent. <br /><h2>Functional Description</h2>
These wooden crystal models were created as educational tools. The intent is to aid in the naming and identification of crystals by type. Each category of models is labeled in a separate box at the A.E. Seaman Mineral Museum. These models are still in use today at Michigan Technological University.
Savannah de Luca
c. 1910
English
Physical object
none
Wooden Crystal Models - Monoclinic/Triclinic
Geology, Mineralogy and Crystallography
<h2>Physical Description</h2>
These crystal models are composed of a lightly colored Pearwood. Each model is precisely shaped with correct angles to illustrate various examples of seven different groups of crystal structures: isometric, tetragonal, hexagonal, orthorhombic, monoclinic, triclinic/trigonal, and twins. Some have been carefully sanded to represent natural curvature of face edges. Because each individual model is unique, the length varies from 3 to 7 centimeters, the width varies from 2 to 7 centimeters, and each has a unique weight. Some have identification numbers carved into them, which pertains to their original kit number given by the manufacturer. Some have hand written numbers in black ink on their flat faces, which identify the name of the crystal they represent.
<h2>Functional Description</h2>
These wooden crystal models were created as educational tools. The intent is to aid in the naming and identification of crystals by type. Each category of models is labeled in a separate box at the A.E. Seaman Mineral Museum. These models are still in use today at Michigan Technological University.
Savannah de Luca
c. 1910
English
Physical object
none
Wooden Crystal Models - Twins
Geology, Mineralogy and Crystallography
<h2>Physical Description</h2>
These crystal models are composed of a lightly colored Pearwood. Each model is precisely shaped with correct angles to illustrate various examples of seven different groups of crystal structures: isometric, tetragonal, hexagonal, orthorhombic, monoclinic, triclinic/trigonal, and twins. Some have been carefully sanded to represent natural curvature of face edges. Because each individual model is unique, the length varies from 3 to 7 centimeters, the width varies from 2 to 7 centimeters, and each has a unique weight. Some have identification numbers carved into them, which pertains to their original kit number given by the manufacturer. Some have hand written numbers in black ink on their flat faces, which identify the name of the crystal they represent.<br /><h2>Functional Description</h2>
These wooden crystal models were created as educational tools. The intent is to aid in the naming and identification of crystals by type. Each category of models is labeled in a separate box at the A.E. Seaman Mineral Museum. These models are still in use today at Michigan Technological University.
Savannah de Luca
c. 1910
English
Physical object
none
Wooden Crystal Models - Hexagonal
Geology, Mineralogy and Crystallography
<h2>Physical Description</h2>
These crystal models are composed of a lightly colored Pearwood. Each model is precisely shaped with correct angles to illustrate various examples of seven different groups of crystal structures: isometric, tetragonal, hexagonal, orthorhombic, monoclinic, triclinic/trigonal, and twins. Some have been carefully sanded to represent natural curvature of face edges. Because each individual model is unique, the length varies from 3 to 7 centimeters, the width varies from 2 to 7 centimeters, and each has a unique weight. Some have identification numbers carved into them, which pertains to their original kit number given by the manufacturer. Some have hand written numbers in black ink on their flat faces, which identify the name of the crystal they represent. <br /><h2>Functional Description</h2>
These wooden crystal models were created as educational tools. The intent is to aid in the naming and identification of crystals by type. Each category of models is labeled in a separate box at the A.E. Seaman Mineral Museum. These models are still in use today at Michigan Technological University.
Savannah de Luca
c. 1910
English
Physical object
none
Wooden Crystal Models - Tetrahedral
Geology, Mineralogy and Crystallography
<h2>Physical Description</h2>
These crystal models are composed of a lightly colored Pearwood. Each model is precisely shaped with correct angles to illustrate various examples of seven different groups of crystal structures: isometric, tetragonal, hexagonal, orthorhombic, monoclinic, triclinic/trigonal, and twins. Some have been carefully sanded to represent natural curvature of face edges. Because each individual model is unique, the length varies from 3 to 7 centimeters, the width varies from 2 to 7 centimeters, and each has a unique weight. Some have identification numbers carved into them, which pertains to their original kit number given by the manufacturer. Some have hand written numbers in black ink on their flat faces, which identify the name of the crystal they represent.
<h2>Functional Description</h2>
These wooden crystal models were created as educational tools. The intent is to aid in the naming and identification of crystals by type. Each category of models is labeled in a separate box at the A.E. Seaman Mineral Museum. These models are still in use today at Michigan Technological University.
Savannah de Luca
c. 1910
English
Physical object
none