Graduate School

Flowstone and its composition

This course is part of the programme:
Karstology (Third Level)

Objectives and competences

The primary goal of this course is to give students the knowledge of flowstone and its formation. Flowstone is chemical sediment deposited from supersaturated water solutions and most often has a calcite composition. Students will learn, that flowstone is not just calcite in its composition. If the composition of the solution changes during the development of flowstone, individual layers will differ in their mineral composition. Calcite is at the same time the most frequent secondary mineral found in karst caves, both in Slovenia and around the world, followed according to quantity by aragonite and gypsum. Students realize that the form of flowstone depends on the mode of water flow, its mineral composition and color on the presence of various ions in solution, that is, on the composition of the overlaying strata. Students will learn about calcite precipitation and the reasons of variously sized crystals growth. They will learn the difference between calcite and aragonite, polymorphs of calcium carbonate, and about the factors that determine which of these minerals will be deposited in a particular environment. For example, the most important factor influencing the deposit of aragonite before calcite is the presence of magnesium and strontium ions in the solution. Students will also discover that gypsum, which is the third most frequently found mineral in karst caves around the world, is not so frequently found in Slovenia.



Content (Syllabus outline)

  • Forms of flowstone and factors that influence its development
  • Minerals in karst caves
  • Calcite
  • Crystal composition of flowstone
  • Recrystallization of flowstone
  • Aragonite and the conditions under which it is deposited
  • Gypsum
  • Flowstone in caves in Slovenia and around the world

Intended learning outcomes

Students learn that flowstone is not only calcite in its composition and that in the caves we can find various minerals which reflect different lithology from its surrounding and the presence of living beings. Learn about crystallography and other properties of the flowstone, formation of various forms of calcite crystals in a specific environment, recrystallization of calcite crystals and environments where precipitation of aragonite and gypsum are preferred. Thus, they acquire knowledge and skills needed for independent research on flowstones.


  • Hill, C. & Forti, P., 1986: Cave Minerals of the World., National speleologica society, 1-238, Huntsville.
  • Hill,C. & Forti, P., 1997: Cave Minerals of the World. Second edition. National Speleological Society, Inc., 463 pp, Huntsville.
  • Herlec, U., Stare, F., Jerek, M. & Zupan Hajna, N., 2006: Kristali sadre v preperini oligocenskih klastitov iz jamskih sedimentov v Bohinju. V: Jeršek, M. (ur.). Mineralna bogastva Slovenije, (Scopolia, Supplementum, 3). Prirodoslovni muzej Slovenije, 219-222, Ljubljana.
  • Knez, M. & Zupan, N., 1992: Minerali v slovenskih kraških jamah. 43pp., Postojna.
  • Zupan Hajna, N., 2006: Siga v kraških jamah. V: Jeršek, M. (ur.). Mineralna bogastva Slovenije, (Scopolia, Supplementum, 3). Prirodoslovni muzej Slovenije, 192-, Ljubljana.
  • Zupan Hajna, N., 2006: Sadrini kristali v kraški jami južno od Velenja. V: Jeršek, M. (ur.). Mineralna bogastva Slovenije, (Scopolia, Supplementum, 3). Prirodoslovni muzej Slovenije, 216-218, Ljubljana.
  • Fairchild I.J. & Baker, A., 2012: Speleothem Science: From Process to Past Environments. First Edition, Blackwell Publishing, 416 pp.


The oral exam is designed to assess the student acquired knowledge from the classes and ability to understand, articulate and expressing their knowledge. Conditions for examination are the presence at the field work, a short essay (5-10 pages), by which the student works on a certain topic related to his seminar and dissertation. 50/50

Lecturer's references

Associate Professor of Karstology


University course code: 3KR037

Year of study: 2

Semester: 2

Course principal:




  • Lectures: 50 hours
  • Seminar: 30 hours
  • Field exercises: 10 hours
  • Individual work: 90 hours

Course type: elective

Languages: slovene, english

Learning and teaching methods:
• lectures • individual consultations • field lectures • field work and preparation of the report • individual work under s under supervision of the lecturer responsible for the course