David K. Joyce

Downs Collection, Arizona Minerals

I am pleased to offer the mineral collection of Dr. Robert T. Downs for sale, here on the website. Dr. Downs was born and raised in Canada and lived in many places across the country. Since a boy he was interested in minerals and mineralogy and has had several mineral collections over the years. Bob was a “late starter” and, after many years working on major construction projects as a supervisor and surveyor In British Columbia and the Yukon, he finally completed a degree in mathematics at the University of British Columbia, at the age of 30. Subsequently, he completed a masters degree and then a PhD in Mineralogy and Mathematics at Virginia Polytechnic. All through his life, he collected and studied minerals and was especially good at field collecting fine and interesting mineral crystal specimens. After post-doctoral studies at the Geophysical Lab in Washington, DC, he accepted a professorship at the University of Arizona, in Tucson. He has contributed much to the world of crystallography and mineralogy over the years, in the field of crystal structures, the RRUF project, supervision of dozens of masters and PhD students, as founding curator of the New Alfie Norville Gem and Mineral Museum in Tucson and in remote sensing and mineralogical analysis for extra terrestrial missions.
The Downs collection reflects his interests over the years, particularly with the Apatite Group of minerals, fluorapatite, vanadinite, mimetite, pyromorphite, etc. As well , other specimens are some very good personally collected specimens from Southern Arizona. There are a number of other pieces that just intrigued Bob for various reasons. Here are some of his mineral specimens.

In this page, you will find specimens that Dr. Downs collected in Arizona at various times, over the years.

All prices in Canadian dollars. For payment in US$, deduct 20% or multiply by 0.8.

Click on any of the following thumbnails to view a larger image of the specimen.

WulfeniteDowns Collection, Arizona Minerals
  • Item #27867
  • Wulfenite
  • 9.0x7.2x4.0 cm
  • Largest Crystal Size: 9mm
  • $95.00
  • Red Cloud Mine
  • La Paz County
    Arizona, USA
  • RTD Two, beautiful, orange-red wulfenite crystals are nicely exposed on this piece. The matrix is composed of willemite (fluorescent greenish) plus other vein minerals. Lots of black coated willemite crystals around the wulfenite. The wulfenite crystals are thick-tabular with truncated edges and small corner faces. Shows well. Collected in 1997.
VanadiniteDowns Collection, Arizona Minerals
  • Item #27870
  • Vanadinite
  • 2.8x1.7x1.4 cm
  • Largest Crystal Size: 3mm
  • $35.00
  • Old Yuma Mine
  • Pima County
    Arizona, USA
  • RTD This small matrix is largely covered by bright, hexagonal prisms up to 3mm in length. Old AZ classic!
WulfeniteDowns Collection, Arizona Minerals
  • Item #29630
  • Wulfenite
  • 3.2x1.9x1.8 cm
  • Largest Crystal Size: 6mm
  • $30.00
  • Pure Potential Mine
  • La Paz County
    Arizona, USA
  • RTD Just a little guy, but nice crystals from an unusual wulfenite locality. Bob collected these specimens with George Godas in 1997.
Wulfenite. QuartzDowns Collection, Arizona Minerals
  • Item #29631
  • Wulfenite. Quartz
  • 7.1x4.1x3.0 cm
  • Largest Crystal Size: 12mm
  • $65.00
  • Pure Potential Mine
  • La Paz County
    Arizona, USA
  • RTD The red-orange crystal on the right practically glows. This very nice crystal is one of two in a quartz lined vug that fills the front of this specimen. A few willemite crystals here and there. Collected with George Godas in 1997. Displays very well.
Vanadinite, CalciteDowns Collection, Arizona Minerals
  • Item #29614
  • Vanadinite, Calcite
  • 7.5x4.7x2.9 cm
  • Largest Crystal Size: 3mm
  • $30.00
  • Pure Potential Mine
  • La Paz County
    Arizona, USA
  • RTD Lighter coloured, bright, vanadinite crystals from the Pure Potential mine. Gemmy crystals associated with white-colourless calcite crystals. Collected with George Godas in 1997.
Wulfenite, WillemiteDowns Collection, Arizona Minerals
  • Item #29606
  • Wulfenite, Willemite
  • 9.3x6.4x5.2 cm
  • Largest Crystal Size: 7.5mm
  • $35.00
  • Red Cloud Mine
  • La Paz County
    Arizona, USA
  • RTD Some very nice, well formed orangey wulfenite crystals on tis specimen, along with small elongated crystal bundles of willemite, that fluoresces green. Classic AZ!
VanadiniteDowns Collection, Arizona Minerals
  • Item #29608
  • Vanadinite
  • 2.6x2.1x1.3 cm
  • Largest Crystal Size: 4.5mm
  • $30.00
  • Old Yuma Mine
  • Tucson
    Arizona, USA
  • RTD A nice little specimen showing perfect, orange-red, hexagonal prisms of lustrous vanadinite.
GypsumDowns Collection, Arizona Minerals
  • Item #29633
  • Gypsum
  • 3.6x3.4x2.6 cm
  • Largest Crystal Size: 5mm
  • $35.00
  • Tiger Mine
  • Gila County
    Arizona, USA
  • RTD A very nice cluster of white gypsum crystals on a matrix showing secondary copper mineralization. Well mounted on an acrylic base. Personally collected by Bob 21 years ago!
Vanadinite, DescloiziteDowns Collection, Arizona Minerals
  • Item #28051
  • Vanadinite, Descloizite
  • 3.8x2.1x1.7 cm
  • Largest Crystal Size: 3mm
  • $40.00
  • J.C. Holmes Claim
  • Patagonia
    Arizona, USA
  • RTD The front of this quartz matrix has many sharp, orange vanadinite crystals showing equally developed pyramid and prism faces. Also clusters of micro, black, descloizite crystals. Classic AZ locality!
WulfeniteDowns Collection, Arizona Minerals
  • Item #28060
  • Wulfenite
  • 1.8x1.5x0.9 cm
  • Largest Crystal Size: 7mm
  • $35.00
  • Rowley Mine
  • Maricopa County
    Arizona, USA
  • RTD A gorgeous little, well formed, tabular, beveled wulfenite crystal on a breccia matrix. The wulfenite crystal is more orange than it appears in the photo. Classic AZ. Sweet!
GypsumDowns Collection, Arizona Minerals
  • Item #29618
  • Gypsum
  • 8.5x6.5x3.2 cm
  • Largest Crystal Size: n/a
  • $65.00
  • Iron Cap Mine
  • Graham County
    Arizona, USA
  • Sort of popcorn-like formations of gypsum on matrix from the famous zinc mine in Graham Co. Striking and unusual!
Wulfenite, MimetiteDowns Collection, Arizona Minerals
  • Item #29617
  • Wulfenite, Mimetite
  • 3.4x2.9x2.2 cm
  • Largest Crystal Size: 8mm
  • $35.00
  • Rowley Mine
  • Maricopa County
    Arizona, USA
  • A single, sharp, thin-tabular, beveled wulfenite crystals sits on matrix, surrounded by tiny, yellow mimetite crystals. The wulfenite is a bit more orange than in the photo. Very nice!!