The Mineralogical Museum is housed in Penny Hall, the Geoscience building. Opened in 1971 and renovated in 2009, the Museum displays approximately 350 specimens, including minerals from the remarkable collection of Irénée du Pont. The du Pont collection was assembled in the 1920s and was gifted to the University in 1964, providing the foundation for further growth.
The present collection contains approximately 3000 specimens of minerals, meteorites, gems and carvings and is divided into a display collection and a reference collection. The display collection focuses on fine crystallized minerals; classics from worldwide and American localities, specimens from significant recent discoveries and themes such as crystallography and crystal growth. The reference collection is comprised of specimens that illustrate crystallography, regional and systematic mineralogy and is used by a wide variety of students in geology, engineering, art conservation and education.
THE IRÉNÉE DU PONT COLLECTION
The Irénée du Pont mineral collection, assembled primarily in the 1920s, was gifted to the University in 1964. Little was known about the history of this fine collection, which became the foundation of the University of Delaware Mineralogical Museum. The research of Curator Sharon Fitzgerald, recently published as a Mineralogical Record supplement (May/June 2015), has greatly enhanced our knowledge about the specimens and their provenance.
Although Mr. du Pont collected minerals from childhood, his first major purchase was a rounded, stream rolled topaz crystal weighing more than 19 pounds that he saw in Tiffany & Co. in New York. George F. Kunz, the Vice-President of Tiffany & Co. required Mr. du Pont to purchase an entire collection in order to have this crystal. That collection included emeralds, bi-color tourmalines in a fitted box, a diamond in matrix and much more. For approximately a decade, Mr. du Pont added to his collection, buying from George Kunz and from George English of Ward’s Natural Science Establishment. In addition to his love of natural crystals, du Pont’s appreciation of rarities, new finds and ore minerals reflected his background as an engineer.
Some of the specimens in this collection can be traced back more than one hundred years to previous owners. One kunzite crystal specimen, the gem variety of the mineral spodumene, can be traced back to the original discoverer of the gemstone. The fall exhibition highlights the early du Pont Collection and includes specimens whose stories have been recently discovered, including the topaz “boulder,” a rutilated quartz and two Arkansas diamonds. The Mineralogical Record supplement, which includes an illustrated catalog of the collection, can be purchased at the Museum located in Penny Hall on 255 Academy Street.
Although the Mineralogical Museum was founded with the gift of the collection of Irénée du Pont, Sr., it has grown to encompass specimens gifted or made possible by many generous donors, including Mrs. David Craven, Alvin B. Stiles and Frederick A Keidel. Because of our intimate space, we have chosen to focus on individual displays that illustrate particular mineralogical concepts or themes. With approximately 350 specimens on view from a collection of more than 2500 specimens, frequent change allows the visitor to see new specimens. This is particularly true with the fall exhibition which reflects the research on the history of the early 20th century collection of Mr. du Pont. The display cabinets with fiber optic lighting provide accurate color balance for specimens from the wire silvers to the vivid orange wulfenites.
All minerals are crystalline, with orderly and repeating arrangements of atoms. Growth occurs by the addition of atoms to the arrangement. If growth takes place in an open space or in soft material, a crystal, reflecting the internal atomic arrangement may form. Although ideal crystals are perfect shapes, many actual crystals are distorted due to variations in growth over time.
Although there are enormous variations in crystal shapes, they can all be grouped into six crystal systems based on the geometry of the internal structure.
The exhibition of minerals from Delaware, Maryland and Pennsylvania includes both specimens from mines that have not operated in decades and others discovered more recently, such as the celestine from Meckley’s Quarry, Mandata, Pennsylvania, collected in 2012. The diversity of the geological environments is reflected in the diversity of the minerals themselves: green pyromorphite from long abandoned lead mines; pyrite from nearby iron mines; and botryoidal apple green wavellite from an operating limestone quarry in Mount Pleasant Mills, Pennsylvania.
UNITED STATES AND CANADA
These minerals illustrate the breadth of specimens found in the United States and Canada. Most of the minerals on display were the by-product of mining operations for copper, lead, zinc and other metals. The term “lunch box” specimen can be applied to some, as miners often removed fine crystal specimens during work hours, sparing them from the ore crushers. There have been few ventures strictly for the mining of mineral specimens.
PSEUDOMORPHS and other GROWTH PHENOMENA
A pseudomorph is a “false form” – one mineral adopting the shape of another; the second mineral is said to be a pseudomorph after the first. Pseudomorphs may be formed in different ways:
- A mineral formed under certain conditions may change to another, chemically similar mineral with a different atomic arrangement, if the conditions change.
- A mineral may be replaced by another that has such a great chemical difference that it is considered a replacement pseudomorph.
- A mineral may coat another, preserving the original shape and forming an encrustation pseudomorph. All of these are illustrated by specimens on exhibition.
Crystals may also deviate from their ideal shapes because of internal defects in atomic arrangement or because of the manner in which the atoms have been bonded to the surfaces of crystal faces during growth. Elongated or twisted crystals sometimes result from these arrangements.
Almost all caves are limestone, with light- colored white to beige stalactites and stalagmites. Other unique cave deposits include vivid pink rhodochrosite stalactities in Argentina, deep green banded malachite formations in Republic of Congo and exotic specimens such as this goethite from Spain.