Photo Atlas of Mineral Pseudomorphism

J. Theo Kloprogge, MSc in Geology, PhD in Geology/Chemistry, is currently Adjunct Professor at the Department of Chemistry, College of Arts and Sciences, University of the Philippines Visayas, Philippines. From 2014 till the end of 2024, he was an Honorary Senior Fellow at the School of Earth and Environmental Sciences, University of Queensland, Australia. He has been teaching analytical chemistry, inorganic chemistry and mineralogy/crystallography for many years. During the past 30+ years Dr. Kloprogge has been working as a mineralogist (in particular clay mineralogy) and spectroscopist. The results of this work have been published in nearly 300 papers in international peer reviewed journals as well as in a number of book chapters (including Dev. Clay Sci. Vol. 7), 6 books (as author and/or editor, including Dev. Clay Sci. Vol. 8) and 1 patent.

Robert Lavinsky, PhD Biochemistry (UCSD), was a crystal collector from the age of 12. He first started participating in mineral shows at the age of 14. He initially planned a career in molecular genetics but his passion for minerals led to a career change, founding www.iRocks.com in 1996. Since then, he has been a full-time mineral dealer and educator (particularly in China and online) and recently had the new mineral, Lavinskyite, named after him. Based in Austin, Texas, Stretch works in the semiconductor industry as a mask design manager, previously in the oil and gas industry as a mud logger. He's also a member of the Mineral Association of Dallas (MAD) and the Austin Gem and Mineral Society (AGMS) where he has held seats on the Board of Directors, Dealer Chairman, Scholarship Chairman, and was chosen as 2013's Rockhound of the Year. Stretch has won several awards exhibiting Pseudomorphs including the national trophy for the American Federation of Mineral Societies, the Friends of Mineralogy award for best educational display and the Desautels award from the Tucson Gem and Mineral Society for best case at the main show in Tucson in 2009. Many of his Pseudomorphs have been published in prominent mineral magazines and books including an article on Pseudomorphs in Extra Lapis #43.