The disruption to geoscience curricula due to the COVID-19 pandemic highlights the difficulty
of making mineral and rock samples accessible to students online rather than through
traditional lab classes. In spring 2020, our community had to adapt rapidly to remote
instruction; this transition amplified existing disparities in access to geoscience
education but can be a catalyst to increase accessibility and flexibility in instruction
permanently. Fortunately, a rich collection of 3D mineral and rock samples is being
generated by a community of digital modelers (e.g., Perkins et al., 2019).
Exposing students to mineral and rock samples is an essential component of most earth-science
classes. However, we lack a widely accepted and accessible method to teach basic rock and
mineral description, identification, and classification other than with physical
hand samples. This impedes online teaching of geoscience, and it
seems obvious that this restricts the potential for growth in online classes. It
discriminates against differently abled students and those unable to attend typical
in-person classes (e.g., Carabajal et al., 2017). Furthermore, the emphasis on physical
samples favors programs with large and diverse sample collections: often older,
better-funded, and more prestigious schools.
Digital samples have the potential to address many of these problems albeit with some
drawbacks. “Virtual Rocks” (De Paor, 2016) have been generated from real samples for as long
as 3D scanning technology has been available but have had limited impact and application.
The development of low-cost and rapid structure-from-motion photogrammetry techniques means
that a model can now be made in less than an hour using a cellphone camera and free or
low-cost software on a consumer-grade computer. Sharing and viewing scientific 3D models is
now routine and 3D printers and virtual-reality headsets are now commonplace in schools and
many homes. So why has this technology not taken off in geology programs?
Impediments to Adoption
Major advances in making digital geoscience data available have not been distributed equally
between or within specific core disciplines. For example, the teaching of petrology has
digital support for intermediate and advanced classes in microscopy, petrography, and
virtual field trips (e.g., Cho and Clary, 2020). However, most efforts are directed to
upper-level classes for geology majors and are less useful for introductory classes where
the most students will engage with rocks and minerals, often for the first and only time.
Personal experience and anecdotal evidence gathered from online discussions support the
conclusion that many faculty feel that students must be able to handle mineral and rock
samples to develop a complete understanding. There is no doubt that elements of mineral
identification are heavily dependent on physical interaction with specimens: hardness tests,
steak-plate tests, heft, and feeling the soapiness of talc, for example. But if these cannot
be replicated in an online environment, is that justification to not use digital models? We
say “no”—many important observations of minerals, and most observations of
rock samples, can be and often must be made by eye. Are field photographs of outcrops
undermined by not being able to “lick the rock”? Here, we describe our first-hand
experiences using digital models during the migration to online instruction in March 2020.
We set out to develop an online collection of digital models of volcanic rocks and textures
in spring 2019 to (1) take advantage of our large and diverse sample collection, including
many unique samples; (2) make models available for remote instruction; and (3) share models
with geoscience educators freely. Upon recognizing that model production was
straightforward, we expanded our target samples to include a small suite of minerals and
rocks for “Introduction to Minerals and Rocks,” a required class for geology majors. As soon
as COVID-19 disruption became critical, we produced models for a representative suite of
rock samples, mainly igneous and metamorphic.
Model Construction and Dissemination
Our photography set-up consists of a lightbox, turntable, LED lights, and an 18 MP digital
camera on a tripod (Fig. 1A), costing less than US$100 without the camera. We use Agisoft
Metashape Pro photogrammetry software (Fig. 1B; annual academic license US$559**) on
graphics-accelerated PCs noting processing time scales with RAM, and processor and GPU
speeds. The model is uploaded to Sketchfab.com (http://sketchfab.com/WVUpetrology; Fig.
1C) where we store and share it. A Sketchfab Pro academic license is US$100. All our models
have digital object identifiers and are free to download. Our workflow (Supplemental
Material1) is explained in a series of YouTube videos (currently in production;
see https://www.youtube.com/watch?v=s6D6xFee7fU). Students can
be trained quickly and be making models the same day. The software struggles to replicate
reflective samples, those with homogeneous color, and those with complex morphologies.
(A) Sample photography setup. (B) Model construction in Agisoft Metashape. (C) Finished
model on Sketchfab.com
Curated Sketchfab Collections
Our most novel action is to divide our samples into thematic collections on Sketchfab.com
(http://sketchfab.com/WVUpetrology/collections) and to
systematically add over 80 other users’ models. As of June 2020, we have collections for
minerals (n = 201), crystallography (53), igneous (320), metamorphic (276),
sedimentary (255) and volcanic (251) rocks, meteorites (26), and fault-related rocks (28).
New models are added daily. Samples range from mundane minerals and rocks essential for
introductory classes through to museum-quality specimens. Samples divide into those that are
labeled and those that come without information to facilitate online quizzes.
Use During COVID-19
Digital models cannot substitute for physical hand samples without changing the structure of
lab classes. Limited assessment data indicate that students enjoy the virtual interaction
and are confident with the technology (Alelis et al., 2015), and that they appreciate the
flexibility it allows (Cho and Clary, 2020). However, students miss the hands-on examination
and testing of specimens, and interactions with other students.
Rather than trying to substitute digital models in extant labs, we redesigned our labs around
the digital models and virtual field trips. Enough models were available to introduce and
apply modal mineral analyses to plutonic rocks and to allow students to reliably identify
phenocrysts and porphyroblasts, for example. Students were able to distinguish between
different rock types and to interpret textural information from the 3D models (e.g.,
bedding, etc.). Where important mineral information is not obvious (e.g., calcite reacting
to HCl), we provide the necessary information in the questions.
Digital models of minerals and rocks are easy to produce and deploy in online classes, and
although imperfect, they have advantages over hands-on samples when labs are redesigned
accordingly. A large and growing collection of samples is being generated on Sketchfab.com, meaning that there has never been an easier
time to include 3D models in your classes.
- Alelis, G., Bobrowicz, A., and Ang See Chiang, 2015, Comparison of engagement and
emotional responses of older and younger adults interacting with 3D cultural heritage
artefacts on personal devices: Behaviour & Information Technology, v. 34,
no. 11, p. 1064–1078, https://doi.org/10.1080/0144929X.2015.1056548.
- Carabajal, I.G., Marshall, A.M., and Atchison, C.L., 2017, A synthesis of instructional
strategies in geoscience education literature that address barriers to inclusion for
students with disabilities: Journal of Geoscience Education, v. 65,
p. 531–541, https://doi.org/10.5408/16-211.1.
- Cho, Y., and Clary, R.M., 2020, Challenges and opportunities for virtual learning in
college geology, in Mintzes, J.J., and Walters, E.M., eds., Active Learning in College
Science: Cham, Switzerland, Springer Nature,
- De Paor, D.G., 2016, Virtual rocks: GSA Today, v. 26, no. 8, p. 4–11,
- Perkins, D., Stene, N., Schultz, A., Bentley, C., and Hollister, R., 2019, Rocks and
minerals—A library of 3-dimensional images for classroom use: Geological Society of
America Abstracts with Programs, v. 51, no. 5,
**Correction: This original version of this article identified the software
as Agisoft Metashape Basic photogrammetry software with an annual academic license price
of US$59, but at press time the authors became aware that Pro is now required. The
article was modified to reflect this.
Manuscript received 28 Apr. 2020.
Revised manuscript received 9 June 2020.
Manuscript accepted 11 June 2020.
Posted 7 July 2020.
© 2020, The Geological Society of America. CC-BY-NC.