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.

HemimorphiteDowns Collection, International Minerals
  • Item #29659
  • Hemimorphite
  • 4.3x2.8x2.5 cm
  • Largest Crystal Size: 35mm
  • $40.00
  • Santa Eulalia
  • Chihuahua
  • A simple cluster of divergent, snow-white hemimorphite crystals from one of the areas that produces the best!
SchorlDowns Collection, International Minerals
  • Item #29627
  • Schorl
  • 6.1x6.3x4.2 cm
  • Largest Crystal Size: 45mm
  • $70.00
  • 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!
Quartz, ChloriteDowns Collection, International Minerals
  • Item #29661
  • Quartz, Chlorite
  • 10.5x6.0x5.5 cm
  • Largest Crystal Size: 11.5
  • $55.00
  • Windsor

  • Quebec, Canada
  • A cluster of quartz crystals from this "alpine cleft" type locality. The largest, a sharp, but bent crystal is heavily included with small crystals of chlorite. Interestingly, the smaller crystals are not included with chlorite. Interesting piece from this long worked out locality! RTD
KoettigiteDowns Collection, International Minerals
  • Item #29647
  • Koettigite
  • 8.0x5.2x2.5 cm
  • $75.00
  • La Mina Ojuela
  • Mapimi, Durango
  • Much of the top of this limonite matrix is covered with grey-blue koettigite, some of it fairly well crystallized. The sprays of vivianite-like crystals are in radiating or divergent clusters and appear to be a little corroded. Still nice!
QuartzDowns Collection, International Minerals
  • Item #29654
  • Quartz
  • 5.5x3.7x2.3 cm
  • Largest Crystal Size:
  • $40.00

  • Brazil
  • Sorry, Brazil is the only locality info that I have for this one. It is an interesting parallel growth of smoky quartz crystals formed on colourless quartz. Very cool looking! RTD
Sphalerite, Quartz, ChloriteDowns Collection, International Minerals
  • Item #29656
  • Sphalerite, Quartz, Chlorite
  • 6.0x3.5x2.0 cm
  • Largest Crystal Size: sph-27mm
  • $40.00
  • Vtoroy Sovietskiy
  • Dalnegorsk, Primorskiy Kray
  • A single, complex, brown sphalerite crystal with a cluster of quartz crystals attached to it. If you look carefully at the bases of the quartz crystals, you'll see a green mineral. The green is composed of many tiny spherical crystals of chlorite. RTD
HemimorphiteDowns Collection, International Minerals
  • Item #29657
  • Hemimorphite
  • 5.0x4.6x3.5 cm
  • Largest Crystal Size: 20mm
  • $40.00
  • Santa Eulalia
  • Aquiles Serdan, Chihuahua
  • Mexico is famous for excellent clusters of hemimorphite crystals. Here is one! A miniature showing white hemimorphite crystals with a divergent crystal habit. RTD
MicroclineDowns Collection, International Minerals
  • Item #29658
  • Microcline
  • 2.7x2.2x2.8 cm
  • Largest Crystal Size: as above
  • $45.00
  • Konzo

  • Ethiopia
  • A very peculiar crystal of microcline which I think would be considered amazonite. The crystal is a bright green with fairly gemmy areas. Interesting and unusual!
StibniteDowns Collection, International Minerals
  • Item #29612
  • Stibnite
  • 7.8x4.7x4.6 cm
  • Largest Crystal Size: 24mm
  • $65.00
  • 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! RTD
Epidote, PrehiniteDowns Collection, International Minerals
  • Item #29634
  • Epidote, Prehinite
  • 3.6x3.0x2.1 cm
  • Largest Crystal Size: e-35mm
  • $35.00
  • Djouga
  • Bendoukou, Kayes
  • RTD A very well formed, dark green epidote crystal atop a light green ball of prehnite crystals. The epidote is doubly terminated and an excellent example of this mineral.
Quartz, var. FadenDowns Collection, International Minerals
  • Item #29637
  • Quartz, var. Faden
  • 6.0x3.8x2.6 cm
  • Largest Crystal Size: as above
  • $45.00
  • Dara Ismael Khan District
  • S. Waziristan
  • RTD Here is an excellent example of a "faden" growth of quartz. It is a certain style of growth, often seen in alpine cleft occurrences where the quartz crystals formed after relatively rapid changes to the cavity opening shape, during mountain building. You can see the faden "string" across the center of the crystal cluster. Crystallized on all sides.
CalciteDowns Collection, International Minerals
  • Item #29639
  • Calcite
  • 5.5x4.2x3.2 cm
  • Largest Crystal Size: 30mm
  • $40.00
  • St. Clothilde

  • Quebec, Canada
  • RTD A cluster of sharp, disc-shaped calcite crystals from this famous quarry in Quebec. The crystals are actually largely flattened rhombohedra with small prism faces, there is a small ding on one of the crystals, as you can see. Nice cluster collected back in 1986!
EpidoteDowns Collection, International Minerals
  • Item #29640
  • Epidote
  • 4.8x3.9x4.6 cm
  • Largest Crystal Size: as above
  • $35.00
  • Quetta
  • Baluchistan
  • RTD Here is a large, blocky, well formed epidote crystal from this famous locale. The crystal is striated with smaller crystals attached to it in a couple of places. Feels great! Looks great!
QuartzDowns Collection, International Minerals
  • Item #29643
  • Quartz
  • 7.1x5.5x3.2 cm
  • Largest Crystal Size: as above
  • $75.00
  • Anahi Mine
  • Santa Cruz
  • RTD An unusually coherent, doubly terminated crystal from this famous "ametrine" locality. The crystal is unusually lustrous, very gemmy and shows mostly amethyst colouration with some areas of citrinous quartz. It is not perfect like most of the crystals from this locality but WAY better formed and preserved than most. Nice crystal!
Koettigite, GypsumDowns Collection, International Minerals
  • Item #29646
  • Koettigite, Gypsum
  • 9.0x5.4x2.6 cm
  • Largest Crystal Size: 3mm
  • $85.00
  • Ojuela Mine
  • Mapimi, Durango
  • RTD The top of this specimen is honeycombed with openings that contain a dozen and a half, or so clusters of grey-blue koettigite crystals. The Koettigite crystals are sharp, well terminated crystals. This is one of the relatively rare minerals that occurs at Ojula Mine, collected many years ago. Accompanied by a Ward's Science Establishment label. Excellent!
EpidoteDowns Collection, International Minerals
  • Item #29648
  • Epidote
  • 5.8x4.7x2.0 cm
  • Largest Crystal Size: as above
  • $75.00
  • Quetta
  • Baluchistan
  • This single, sharp crystal of epidote has a tabular crystal habit. It is lustrous all over but the lustre is partly obscured by loads of tiny, epidote crystals that partly cover most of the crystal faces. Some smaller epidote crystals are on the back of the main crystal. Really nice crystal!
CorundumDowns Collection, International Minerals
  • Item #29615
  • Corundum
  • 5.0x2.8x2.4 cm
  • Largest Crystal Size: as above
  • $35.00
  • Soutpansburg Range
  • Limpopo
    South Africa
  • RTD A well formed simple, doubly terminated, blue-grey corundum crystal from this famous corundum producing area of the world. The crystal has triangular terminal markings on one of the terminations. Excellent example!