Mindat.org Management Team

Jolyon Ralph

Jolyon is the founder of mindat.org. He started mindat as a personal mineral information database in 1993, which was later launched as a web site in October 2000. He also runs the gemdat.org website with his wife Katya. They have a young son, Roman, born in 2014.

Area of expertise: British Minerals

Alex Venzke

Alex Venzke is a member of the leadership team of the Young Mineral Collectors group, a member of the mindat.org management team, a board member for the national Friends of Mineralogy organization, a former board member of the Mineralogical Society of the District of Columbia, and co-founder and first Vice President of the Friends of Mineralogy Virginia Chapter.

Alfredo Petrov

Alfredo Petrov: Geologist, collector of microminerals and geological oddities, member of the management team since Mindat first went online in 2000, currently living in California. On Mindat, primarily works on locality information for Japan, Bolivia, Argentina. First field collected specimens were selenite crystals from a clay pit in Bracknell, England, at 7 years old, and ever since then has been in battle over how many rocks are allowed in the house.

Andrew G. Christy

Mindat Manager since 2006. Main managerial actions have been to add, complete and correct information on mineral data pages on an ad hoc basis. Relevant expertise is mainly in crystallography, crystal chemistry, optics, analytical methods, mineral characterisation and classification, mineral associations and paragenesis rather than in specific regions or localities.

Bill Cordua

Bill is proud to be part of the management board. He is a retired geology professor, with nearly 40 years of teaching experience at the Univeristy of Wisconsin- River Falls. for MINDAT he has done major work editing entries for Wisconsin, Minnesota, Iowa, Indiana, Maryland, Delaware, Virginia, West Virginia and the District of Columbia.

Christof Schäfer

Christof Schäfer, mining engineer and amateur mineralogist for more than 35 years with main focus on volcanic minerals especially those from Mt Vesuvius and the Eifel area. If he finds the time he adds and corrects data.

Dale Foster

Dale Foster is a mining geologist, graduate of the Camborne School Of Mines (ACSM93) specialising in dealing with the legacy of mining activity in Cornwall and Devon.

He developed an interest in mining and minerals from an early age.

As an enthusiast he has visited and photographed almost all of the surviving mining related structures in Cornwall along with a fair number of Devon sites as well.

In regard of mineral collecting his main area of interest and specialism is tin / tungsten ore from Cornwall and Devon, however, if anything else has caught his interest that will also find a home in his collection.

David Von Bargen

Trained as professional mineralogist and have been mineral collector for 60 years. Interested in topographical mineralogy and geological literature from the 1850's to 1920's. Program on the mindat website to provide data integrity and user ease of use issues.

Debbie Woolf

Debbie is a housewife and a small business owner in garden machinery. Since the millennium Debbie has had a passion for minerals and found 'mindat', her area is South Africa and Namibia.

Erin Delventhal

Erin works in an officious capacity in areas including project management, graphic design, publicity, etc. Occasionally, she knows something about a mineral.

Frank de Wit

Fieldcollector, from beach to mountains, in quarries and underground, in alpine clefts, burning coaldump vents and volcanic fumaroles. And while at home wasting time on mineral websites and maintaining mineral data.

Frank K. Mazdab

Frank has been collecting minerals, and sometimes doing chemistry experiments on them, since age 10. Now a professional mineralogist, with a focus on ore deposit-related mineral assemblages, mineral chemistries, and the microbeam analytical techniques needed to try to figure all that out. The thin sections featured on Frank's petrology-focused website rockPTX.com pretty much all link back to mindat localities.

Areas of expertise: optical mineralogy/petrography, systematic mineralogy, crystal chemistry, mineral analysis (EPMA, SIMS, ICP-MS)

George R. Rossman

George R. Rossman is Professor of Mineralogy at Caltech, in Pasadena, California, and a research collaborator with the Natural History Museum of Los Angeles County, the American Museum of Natural History, and other researchers, world-wide.

Areas of expertise: origin of color, spectroscopic methods of mineral analysis and identification.

Georges Favreau

Georges has liked minerals since he was a kid, but decided that becoming a computer engineer would be better for a living. His greatest pleasure is to go collecting on the field in company of friends who share his weird love for microscopic crystals. When he is not in his favourite places in the South of France, Morocco, Spain, SW of the USA, he dreams of travelling back there.

Harjo Neutkens

Harjo studied arts (painting) and music (early plucked instruments), he lives in a small Dutch village with his wife Rachel, who is an arts teacher, and they have a beautiful talented daughter, Sarah, who is a composer, artist and model.
When Harjo isn't playing concerts or creating his artwork he can be found collecting minerals in the mountains, in quarries, in mines or on mine dumps. He can also often be found sitting behind his camera making mineral micro photos.

Area of expertise: Belgian minerals and to a lesser extent the minerals of the Hohe Tauern region of Austria.

Jean-Marc Johannet

Agronomy engineer by hazard - he wanted to be a geologist but he failed at the entrance examination - he works, now, as a biomass recycling project manager. So, the Earth Sciences and specially mineralogy became his passion instead of his job. Surely better like that !
Mineral collector since he was a teenager, he started to collect only micro-minerals since 30 years when he began to move frequently.
As a Mindat Manager (since 2010) he adds, makes updates, checks and corrects the locality pages for France.
Main interests : phosphate and uranium minerals and photography.

John Rakovan

As a Mindat manager I work on different aspects of mineralogy and much that is related to apatite and apatite group minerals.

José Zendrera

A decade ago I was upgraded to level 2 by Rob Woodside in order to help improving Pakistan, Afghanistan and Nepal information due to my first hand (little) knowledge on these countries. After years reviewing new photos and adding data, at the end of year 2022 Rob proposed me to enter in the management group. Even knowing that my mineralogical level is quite limited, my English very poor and that perhaps it would not be up to the task, I accepted pushed by my admiration for Mindat, of which I like almost all from data content to pages design, even their occasional blackouts.
Thanks for accepting me in this magnificent team.

Keith Compton

Keith is a chartered accountant, now semi-retired, who has collected minerals since he was about 12 years old. Keith has been a manager since 2016. He is active in adding to, and improving, locality data and references, particularly those in Australia, New Zealand, Papua New Guinea and other South Pacific localities.

Areas of expertise include Australia generally with particular focus on New South Wales.

Kevin Conroy

Kevin has been collecting minerals for the vast majority of his life, with Missouri, Illinois, Colorado, Arizona, UK and Tsumeb minerals being of special interest. He used to set up a several shows every year (with Denver and Tucson among his favorites) to peddle a few specimens, but now he would rather walk around to see what everyone else has, and catch up with friends.

Knut Edvard Larsen

Knut Edvard Larsen is a Norwegian amateur mineralogist and has been a passionate mineral collector (systematic) since he was 13. By profession he is a theologian (missiologist). Co-editor of the STEIN magazine He has written several articles, and is active in the mineral community in Norway.
As a Mindat Manager (since 2009) he add, update, check and correct locality and mineral pages.
Area of expertise: Madagascar and Scandinavian Minerals, especially Norwegian.

Knut Eldjarn

Knut Eldjarn is a medical doctor by profession and currently president of a biotech company that manufactures quality controls for laboratories world wide. He has been a dedicated mineral collector since childhood more than 50 years ago. He has had a life long passion for self collecting and studying specimens and rare species from a wide variety of localities especially in Scandinavia and Greenland. He is currently trying to recruit future collectors and mindaters hosting a very local rock club among the mineral display cabinets with his 6 grandchildren and contributing to Mindat when time allows.

László Horváth

László Horváth, Canadian amateur mineralogist and field collector for the last 44 years, specializing in the mineralogy of Mont Saint-Hilaire and other alkaline complexes worldwide, miscellaneous Québec localities and Canadian type minerals.

Marco E. Ciriotti

Italian member of the IMA CNMNC; Member of IMA UM (Unnamed Minerals) Commission; Founder and president of AMI (Associazione Micromineralogica Italiana - Italian Micromineralogical Association); Founder and President of the Editorial Board of Micro (a mineralogical journal); Member of the Research Mineralogical Group at the Department of the Earth Sciences of the University of Torino (the group includes Fernando Cámara, Erica Bittarello, Cristian Biagioni, Luca Bindi, Fabrizio Nestola); Systematic Collectors.

Area of expertise: Systematic mineralogy, crystallography and crystal chemistry, minerals from Italy.

Mike Rumsey

Mindat manager for over ten years and a Senior Curator in a National Museum with responsibility for mineralogical, gemmological and meteoritic collections and staff. Living just a few miles form Jolyon in London allows me the rare opportunity as a manager to have face-to-face meetings where we share and review big-picture ideas and opinions about the site, mineralogy in general and the different facets of mineralogical outreach and increasingly research in the local pub.

Nathalie Brandes

I have been active in geology since following my father (also a geologist) into the field as soon as I could walk. I am currently a professor of geology at a college in the United States, although I have lived and worked in several countries over the years.

Areas of expertise: geology of the Colorado Plateau, geology of New Mexico, geoarchaeology (especially ancient mining), history of classic mining localities.

Olav Revheim

Olav is a Petroleum Engineer of profession and his interest in mineralogy, petrology and geology is on an amateur level. He enjoys field collecting and is fortunate to have some decent localities not too far away from Krstiansand, Norway where he lives. His main contribution to mindat is as a participant in the Best Minerals project in addition to a fascination for the amphiboles.

Paul Brandes

Paul Brandes is a professor of geology, author, world traveler, and award-winning geologic photographer currently living in Texas. Growing up on the Keweenaw Peninsula of Michigan, he has been interested in minerals and geology for as long as he can remember. He was the original discoverer and researcher of the new mineral Centennialite, a calcium copper chloride from the Centennial Mine in Michigan. With his geologist wife Nathalie, they travel the world in search of new and exciting places to study geology and add to their mineral collection.

Areas of expertise: Great Lakes geology/minerals and Precambrian geology.

Paul De Bondt

Paul De Bondt is a biochemist and an amateur mineral collector and contributed to several mineralogical magazines and books. He collect since his childhood and specialises in Katanga, Tsumeb, Cornwall and Ste Marie minerals.
He works on Mindat since 2008 by adding and improving data and as a manager since 2014.

Areas of expertise, Katanga and the U.K.

Pavel Kartashov

My area is countries of former Soviet Union and Mongolia.

Pavel Martynov

The intro will be here soon

Ralph S Bottrill

Ralph Bottrill is a geologist, mineralogist, petrologist and mineral collector, living near Hobart in Tasmania, Australia. Specialising in minerals from Tasmania, Broken Hill, South Australia and quite a few other areas. He runs the state mineralogy/petrology laboratories and rock collections, studies Tasmanian mineral deposits and occurrences (field and lab) and does some general geology and database work. He is an associate curator for minerals with several Tasmanian Museums, an associate editor of the Australian Journal of Mineralogy, and president of the Mineralogical Society of Tasmania.

Areas of expertise include Tasmania, Australia, geology, petrology and general mineralogy.

Rob Woodside

Rob Woodside is a retired college physics teacher who has collected minerals since he was 8 years old. For many years he collected elements and sulfides systematically, attempting to find small hand specimens with the best crystallization. Recently that collection was sold and I started collecting odd things like polymorph specimens where at least two chemically identical, but structurally different, minerals occur on the same piece, etc. He just loves minerals.

Robert Meyer

Greetings, fellow members of Mindat.

Roger Lang

Hi all!
Collecting (more or less ;-) since 1975. I studied mineralogy at the Aachen Technical University (RWTH) with the focus on economic geology and received my degree in 1994. Since 1999 i am working at the Geological Survey of Rhineland-Palatinate in Mainz, Germany.

Ryan Hamel

Ryan manages the technical aspects of the mindat server. He is not a geologist nor a rock collector, but has contributed many weeks into monitoring, optimizing, and fixing various aspects of the website along side Jolyon, David, and Pavel. During the day Ryan is a network engineer supporting companies with high traffic volumes.

He got into mindat by writing a chat bot in Alyssa Kaess's Twitch stream named "GeologyChad", which scrapped information off of the mineral and glossary pages, and struck up a number of tech conversation with Jolyon a few times in Discord.

Areas of Expertise: Network Engineering, Systems Administration, Website Design and Optimization

Steve Rust

I am a manager on this site interested in the Leadhills/Wanlockhead area, and Penberthy Croft Mine, Cornwall also mid-Wales area.

Tama Higuchi

Tama Higuchi of Dallas, Texas, is a watercolorist and seasoned collector with a focus on aesthetic thumbnails. She is honored to be a member of the board of directors for the Hudson Institute of Mineralogy, and as a manager of the ever-indispensable Mindat.org. Tama is also on the leadership team of the Young Mineral Collectors, a group dedicated to fostering a community and love of learning within the younger demographic of mineral enthusiasts.

Tony Nikischer

Tony Nikischer is:

President of Excalibur Mineral Corporation, dealers in rare minerals for researchers, museums and private collectors;

Chairman of the Board and founder of The Hudson Institute of Mineralogy, an IRS-approved 501(c)3 tax exempt foundation dedicated to descriptive mineralogy, mineral preservation and education. The Institute is the parent organization of mindat.org, its primary outreach vehicle.

Publisher of the monthly magazine "Mineral News". Articles on this home page were originally published in that periodical;

Director (retired), Friends of Mineralogy;

Recipient of the 2011 Charles A. Salotti Earth Science Education Award

Mineral namee for the ugly green mineral Nikischerite.

Uwe Kolitsch

Professional mineralogist (Curator of the Mineral and Ore Deposit Collections at the Natural History Museum Vienna). As a Mindat Manager (since 2005) in my spare time, I mainly add, update, correct and generally improve locality and mineral pages.

Area of expertise: Systematic mineralogy, crystallography and crystal chemistry, ore deposits, secondary minerals, slag "minerals", rare minerals, minerals from Austria.

Vandall Thomas King

Van is happy to be able to contribute to Mindat as a manager and as a board member of the Hudson Institute of Mineralogy. Van's particular interests at Mindat includes editing mineral pages, searching for descriptive and technical data, and locating images of mineralogists and historical details of their careers. Because many historical mineral occurrences are poorly reported, Van has attempted to glean clues to narrow the actual area where historically significant localities were located.