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

This is the only course of its kind in Ireland and one of the few available at university level across Europe. Students also have the opportunity to attend a Diamond Grading course at the Gemmological Association of Great Britain in London, and a Gem Faceting course at the University of Barcelona, allowing them to experience Gemmology abroad and potentially expand their future career prospects.

Students of the Diploma in Gemmology 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 or in gemmological laboratories.

Graduates secure a wide range of roles that reflect the diverse and evolving needs of employers across industries, such as:

• jewellery designers
• goldsmiths & silversmiths with jewellery suppliers
• valuers in auction houses
• diamond specialists for jewellery companies
• lapidary experts working for gemstones suppliers

Many graduates also go on to found their own companies, applying their skills and collaborating with jewellers, designers, and collectors to provide expert advice on gemstone selection, sourcing, and valuation.

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

Please note that several experts will be invited as guest lecturers throughout the two years of the course. 

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.

This course is delivered via Blended learning, which includes online classes and hands-on practicals delivered on campus.

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 492129
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.

Technical & Scientific Transferable Skills

• Advanced Analytical Techniques: Proficiency in operating specialised instruments, such as microscopes, refractometers, and spectrometers is a core gemmology skill that is valuable in other scientific fields and laboratories worldwide.
• Data Analysis and Interpretation: accurately record, scan, organise, and interpret complex numerical and qualitative data to evaluate gemstones, a skill applicable to research, finance, and quality control roles.
• Research Skills: The ability to devise research questions, implement research plans, and conduct thorough literature reviews and data collection is fundamental to gemmological research and transferable to academia, market analysis, and product development.
• Quality Assurance & Control: Establishing and following rigorous protocols for assessing quality and detecting treatments or synthetics translates directly to roles in manufacturing, quality control, and auditing across various sectors.
• Attention to Detail & Observation: The meticulousness required to spot minute inclusions or subtle colour nuances in gemstones is a key observational skill valuable in many precision-oriented professions, such as forensic science, editing, or technical inspection. 

Soft & Interpersonal Transferable Skills

• Problem-Solving: Diagnosing unusual gem characteristics and identifying unknown materials hones strong problem-solving and critical thinking abilities.
• Communication & Presentation: Gemmologists need to clearly explain complex scientific concepts and value factors to clients, colleagues, and non-experts, both verbally and in professional written reports.
• Ethical Judgment: A strong awareness of ethical, social, and environmental implications within the gemstone pipeline fosters sound ethical judgment applicable in business, compliance, and non-profit sectors.
• Independent & Collaborative Work: Gemmology training often requires the ability to work independently on research projects and collaboratively within a team or laboratory setting.
• Time and Project Management: Students develop effective self-motivation, organization, and project management skills to manage complex evaluations and research plans.

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. 

NB: The next intake for this course will be September 2027.

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