The course aims to provide the student with a broad introduction to the study of gemstones. It teaches a range of laboratory–based techniques used to identify gemstones and provides the student with hands-on experience in identification protocols using a comprehensive collection of gemstones. The course also includes studies of typical geological settings of gemstones during lectures.

The course consists of lectures, laboratory demonstrations and practicals including tuition on good practice in the identification of gemstones from the course’s teaching collection which comprises in excess of 1000 cut stones. The course also focuses on the examination of these gemstones using a range of laboratory instruments including binocular microscope, refractometer, spectroscope, polariscope and conoscope.

The course includes the following topics:

• The Dynamic Earth
• Earth History
• Earth Materials
• The Formation and Geological Settings of Gemstones
• Global Distribution of Gemstones
• The Crystallography and Mineralogy of Gemstones
• The Optical Properties of Crystals Gemstone
• Properties and Instrumentation
• Recording Gemstone Properties/Identification
• Protocols
• Fashioning of Gemstones
• Synthetic Gemstones (Enhancements and Imitations)
• Systematic Recording of the Physical and Optical
• Properties of Gemstones

The option of attending a 1-day Diamond Grading course at the headquarters of the Gemmological Association of Great Britain in London will also be available to 2nd-year students.

Students of this course find employment in gemmological work (quality control, authentication) and jewellery (retail and design) trades. Students may also find work as valuators for the insurance industry.

Dr. Alessandra Costanzo,
School of Natural Sciences,
Earth & Ocean Sciences

All modules in the Diploma are individually assessed. Assessment is by examination (written and practical) at the end of each semester and by continuous assessment. This is a two-year, part-time course. Classes and learning material will be delivered online with practical workshops to be carried out at University of Galway on a monthly basis.

As this course is delivered via Blended learning most of the material is delivered online, please visit to our Online Learning webpage for further details on what is required to participate in a blended learning course.

Dr. Alessandra Costanzo
School of Natural Sciences, Earth and Ocean Sciences
Tel: 091 492087
Email: alessandra.costanzo@universityofgalway.ie

If you do not meet the standard entry criteria for this course, you may gain entry through our Recognition of Prior Learning (RPL) policy. Applicants may also be able to earn module exemptions based on their prior learning. Find out more here.

There are no specific entry requirements for the Diploma in Gemmology. Entry requirements for part-time students (e.g. age, English language requirements, etc.) can be found here. 

Applications are made online via the University of Galway Applications System. This course is listed under Adult Learning Undergraduate\Postgraduate, CPD, Micro-credentials & Summer School Applications.

Please visit our How to Apply page for Application tips and Supporting Documents information.

Fees for Academic Year 2026/27

A fee scholarship of up to 30% may be available for students who wish to upskill for the purposes of re-employment. For more information download the 2025_26 Fees Scholarship Form