History of Gemmology

Introduction

Gems always used as adornment or symbols of power. Initially humans used coral, shell, bone, feather, teeth, claws, pearls and seeds. Looked for visual beauty, rarity and durability. Then started to collect rocks & minerals. Some of the oldest on record include green nephrite jade, banded agate and light blue turquoise. Greek and Romans wrote about properties of precious stones. The interest was in rarity, healing and religious properties. Eg: Roman beads, one emerald and one quartz. the quartz was once dyed to mimic the emerald. As fake stones become more sophisticated there was a need to ID & separate enhancements from natural stone. Increased technology allowed stone to be cut & polished to reveal sparkle or shifts in colour (optics). This was the start of gemmology.

Medieval and Renaissance Europe elaborated on distinguishing one stone from another and how to modify appearance using gem treatments. Mainly used criteria of visual appearance, weight and resistance to scratching. Was not until the early 19th century with the development of chemistry and earth sciences, such as mineralogy and crystallography, that classification and ID advanced. Yet some methods destroyed/damaged the stones. Development in information on how gems interact with light and chemical composition. Used methods that did not damage the stone. This was the beginning of the science of gemmology.

• 1890 London had gemmology workshops.
• 1900 the first commercially available lab grown ruby was grown. Synthetic rubies caused a stir in consumer confidence as artifical products could be misrepresented and sold as valuable natural rubies.
• 1908 the National Association of Goldsmiths (NAG) had the first gemmology class to provide training to ID imitations.
• 1913 First gem'l diploma.
• 1931 Gemmological Association of GB established under NAG.
• 1938 Gem-A became independent. Continues to provide education and provide customer confidence in the jewellery trade to train professions and make informed business decisions.

What is Gemmology?

Study of gem material using non-destructive methods to obtain visual, physical and chemical data to ID a material as natural, synthetic or artificial. Want to determine general characteristic, treatments and geological origin. Relevant information on gem materials protects consumer confidence.

Originally seen as an interdisciplinary topic using scientific knowledge from various fields. 20th century technology developed to collect data to enable correct ID. With the increase of treatments and lab grown gems it has had to develop into a science of its own. Industry now worth US$20-25 bill/year. Need to study gem materials to ID frauds. Gemmologist needs to develop observational skills, visual memory, experience in handling and perform tests to confirm gem materials' nature. Need to build 'sight ID' = ID based on visual characteristics which can be backed up with test data.

Ask question like - what is it / natural or synthetic / any treatments to improve or alter it? There have been advancements in synthetic gems that make ID harder. Treatments have become more sophisticated. The industry then need to develop as well to meet the challenges.

Why is knowledge of gems important to those in the industry? Info is needed to value an item:

• separate natural vs synthetic vs artificial.
• verifying if there are any treatments eg: ruby can be fracture-filled with lead glass to improve the clarity, blue flashes will indicate this.
• determining geological origin - some areas are valued more due to history, rarity or colour eg: around Mogok, Myanmar, is more prestigious for rubies.
• assess durability and quality.
• also to know how to care for stones.

Using Laboratories

Have advanced analytical equipment, more accurate than hand-held equipment. You need to be aware of your limitations and get another, objective opinion. Highly qualified staff. Labs can tell the grade to give diamonds. Is an emerald natural or synthetic? Is a ruby heat treated?

Some results are straightforward such as weight, cutting style and dimensions. Others are more subjective / expert opinion such as clarity, colour, geological origin.

Can be a simple lab or more highly advanced so need to research a lab, scope their capability, before you use it. The designation 'lab' is not broadly regulated. Labs can offer different opinions so not unusual to request two reports to accompany a stone. Differences relate to experience of the staff, technology used and overall criteria used to make a determination.

Labs are related to the valuation/commercial aspect of a stone but they give impartial info on the ID & nature of a material. Lab documents are called reports not certificates.

Gems and the new science

'Gems and the new science: matter and value in the scientific revolution' by Michael Mycroft, Chicago, University of Chicago Press, 2026.

(p.34) Gems were classified according to where they came from. This explains the rise in distinction between oriental and occidental gems in natural gems, in the 16th century. A result of European expansion into the Americas and Indian Ocean. Gems also reclassified due to the growth in lapidary arts in Florence and Prague. Cutters were sensitive to hardness of stones and equated it with brilliance. Notion of hard oriental and soft occidental developed. (p.35) Ths emerged within an older framework - the basic principle of grouping stones by colour and locality as stated by Pliny. (p.45) oriental considered duperior. (p.50) Florentine sculptor Cellini, only four precious stones - ruby made of fire, sapphire of air, emerald of earth and damond of water. (p.63) Renaissance naturalists revived and codified a scheme inherited from Pliny, while expanding that to include he hard/soft distinction and the oriental/occidental distinction (a variant of ancient practice of defining stones by place of origin). (p.64) Renaissance gem classification had a place for colour, trnasparency, hardness and locality but density and double refraction would not become part of the schemes until the end of the 18th century.