Buying & Care Guides

Gemstone Durability: Hardness, Toughness and Stability

Durability is more than a number on the Mohs scale. A gemstone's response to scratching, impact, heat, and chemicals involves different properties.

Understanding those differences helps you ask better questions about settings, daily wear, and cleaning.

Hardness: resistance to scratching

Hardness describes resistance to scratches and abrasion. The Mohs scale provides a relative comparison between materials.

A high hardness does not make a gem unbreakable. Diamond, for example, is highly scratch-resistant but can still chip or fracture under an unfavorable impact.

Toughness: resistance to breaking

Toughness concerns how a material resists breaking, chipping, or cracking. It should not be assumed from hardness alone.

The individual item's fractures, shape, condition, and setting may be relevant to practical risk. A professional should consider the actual stone when advising on a design or repair.

Stability: response to conditions

Stability concerns resistance to influences such as heat, chemicals, and thermal shock. Treatments or assembled constructions can introduce further care considerations.

A cleaning method suitable for one piece of jewelry may be unsuitable for another that looks similar.

Choose a setting with the stone in mind

Discuss the intended wear, exposure to impact, and protection of vulnerable areas. Ask how points, corners, or existing condition concerns affect the design.

The discussion should consider the complete piece rather than the gemstone name alone.

Share the available information

Give your jeweler the report, treatment disclosures, and any history of damage or repair. If the material is uncertain, clarify identity before selecting an aggressive cleaning or repair method.

Build care into ownership

Store pieces so they do not rub against one another, seek inspection when an item has been struck or a setting appears loose, and keep records of professional work.

The objective is not to avoid wearing gemstones. It is to understand the item well enough to choose appropriate care and use.

Further reading: GIA: Gemstone durability and diamond chipping