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 20% or multiply by 0.8.

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
    Mexico
  • A simple cluster of divergent, snow-white hemimorphite crystals from one of the areas that produces the best!
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
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
    Russia
  • 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
  • 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!
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
    Pakistan
  • 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!
Koettigite, GypsumDowns Collection, International Minerals
  • Item #29646
  • Koettigite, Gypsum
  • 9.0x5.4x2.6 cm
  • Largest Crystal Size: 3mm
  • $85.00
  • Ojuela Mine
  • Mapimi, Durango
    Mexico
  • 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
    Pakistan
  • 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!