David K. Joyce

Downs Collection, International 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.

This page offers various minerals from famous localities that Dr. Downs found intriguing or beautiful.

All prices in Canadian dollars. For payment in US$, deduct 18% or multiply by 0.82.

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

Quartz, var. AmetrineDowns Collection, International Minerals
  • Item #27849
  • Quartz, var. Ametrine
  • 6.5x2.7x1.9 cm
  • Largest Crystal Size: as above
  • $120.00
  • Anahi Mine
  • La Gaiba, Sandoval, Santa Cruz
  • RTD An etched crystal of "ametrine, showing about one third as citrine and the rest as amethyst. I expect that this is probably a shard of a once larger crystal and reflects just a couple of the zones. Very interesting piece. Could cut several nice ametrine gems or just be enjoyed for the mineralogical curiosity that it is!
SchorlDowns Collection, International Minerals
  • Item #27858
  • Schorl
  • 6.1x6.3x4.2 cm
  • Largest Crystal Size: 45mm
  • $195.00
  • Erongo

  • Namibia
  • RTD An excellent example of this tourmaline group mineral from the area that produces some of the best. The schorl crystals on this specimen are equant, highly lustrous and pitch-black. They are doubly terminated and hemimorphic, like most tourmalines. Stands just like this for display. Beautiful example of this mineral!
Aegirine, Microcline, Parisite ps.Downs Collection, International Minerals
  • Item #27834
  • Aegirine, Microcline, Parisite ps.
  • 6.6x7.3x3.1 cm
  • Largest Crystal Size: 31mm
  • $230.00
  • Mount Malosa
  • Zomba
  • RTD A stunning cluster of pitch-black aegirine crystals associated with creamy-whitish microcline crystals. The aegirine crystals are amazingly sharp prisms with terminations that are steep pyramids. There are also some pseudomorphs on the speicmen that were parisite crystals that have been replaced by a mixture of Ce-rich rare earth minerals. Beautiful specimen! Displays very well! Way better than in the photographs.
Babingtonite, Prehnite, QuartzDowns Collection, International Minerals
  • Item #27838
  • Babingtonite, Prehnite, Quartz
  • 5.2x4.2x2.8 cm
  • Largest Crystal Size: b-17mm, p-15mm, q27mm
  • $225.00
  • Qiaojia
  • Yunnan
  • RTD A really nice miniature specimen showing a sharp, composite babingtonite crystal sitting atop a cluster of sharp, colourless quartz crystals and light green hemispheres of prehnite. The hemispheres are actually a darker green than shows in the photo. Wonderful babingtonite crystal! Great looking specimen!
StibniteDowns Collection, International Minerals
  • Item #27991
  • Stibnite
  • 7.8x4.7x4.6 cm
  • Largest Crystal Size: 24mm
  • $180.00
  • Baia Sprie

  • Romania
  • RTD This specimen is a cluster of stout, well terminated stibnite crystals from one of the most famous localities for this mineral. There are a couple of crystals missing but that is not very noticeable. Displays very well!
Pyrite, ps. MarcasiteDowns Collection, International Minerals
  • Item #27994
  • Pyrite, ps. Marcasite
  • 9.6x7.5 cm
  • Largest Crystal Size: 92mm
  • $120.00
  • Nanisivik Mine
  • Baffin Island
    Northwest Territories, Canada
  • RTD This piece is one large pseudomorph of pyrite after marcasite with oriented overgrowths of pyrite on the pseudomorph! Kind of like an armour-plated marcasite crystal! Excellent luster. Stands perfectly for display!
QuartzDowns Collection, International Minerals
  • Item #28008
  • Quartz
  • 3.7x3.1x2.5 cm
  • Largest Crystal Size: as above
  • $75.00
  • Pilot

  • Virginia, USA
  • RTD A doubly terminated, parallel growth crystals with a few extra crystals attached to one side. No obvious point of attachment. From a road cut! Excellent!