Why Are Rubies Used in Watches? Exploring Their Role and Benefits

AvatarByArmando Lewellen General Watch Info

When you glance at a finely crafted mechanical watch, you might notice tiny, gleaming red dots nestled within its intricate movement. These are not mere decorative touches but are actually rubies—precious gemstones playing a crucial role in the watch’s performance and longevity. The use of rubies in watchmaking is a fascinating blend of tradition, science, and craftsmanship that has stood the test of time.

Rubies have been integral to horology for centuries, valued not just for their beauty but for their unique physical properties. Their hardness and smoothness make them ideal for reducing friction and wear in the delicate gears and pivots of a watch. This subtle yet vital function helps maintain precision and extends the life of the timepiece, ensuring that it keeps ticking accurately through the years.

Beyond their practical benefits, rubies also symbolize the artistry and meticulous engineering behind high-quality watches. Understanding why these gemstones are used opens a window into the complex world of watch mechanics and the enduring quest for perfection in timekeeping. In the following sections, we will explore the reasons behind the use of rubies in watches and uncover how these tiny gems contribute to the marvel of mechanical watchmaking.

Properties of Rubies That Enhance Watch Performance

Rubies are preferred in watchmaking primarily due to their exceptional physical and chemical properties. One of the most critical attributes is their hardness. On the Mohs scale, rubies rate a 9, making them one of the hardest natural materials after diamonds. This hardness ensures minimal wear and tear when used as bearings in the watch mechanism, thereby prolonging the watch’s lifespan.

In addition to hardness, rubies possess excellent thermal stability. Watches undergo temperature fluctuations during daily wear, and materials that expand or contract significantly could disrupt the precision of the timepiece. Rubies maintain dimensional stability under varying temperatures, which helps keep the watch’s movement accurate.

Another significant property is their low friction coefficient. When watch gears and pivots move, friction can cause energy loss, wear, and inaccuracies. Rubies, being smooth and hard, reduce friction between moving parts, which is essential for the smooth operation of mechanical watches.

The chemical inertness of rubies also plays a vital role. They are resistant to corrosion and oxidation, which means they remain stable even in humid or chemically aggressive environments. This durability ensures that the internal watch mechanism remains protected over decades.

Functional Roles of Ruby Bearings in Watches

Ruby bearings serve several crucial functions within a mechanical watch movement:

  • Reducing Friction: By acting as low-friction pivot points, rubies minimize resistance that would otherwise degrade the watch’s precision.
  • Increasing Longevity: The hardness of rubies limits wear on metal parts, reducing the need for frequent servicing.
  • Enhancing Accuracy: Stable, low-friction pivot points contribute to consistent gear movement, ensuring timekeeping accuracy.
  • Supporting Complex Mechanisms: In complicated watches with multiple moving parts, ruby bearings help maintain smooth operation and reliability.

These functional benefits are why most quality mechanical watches include synthetic rubies as standard components.

Comparison of Ruby Bearings with Other Materials

While rubies are the most common choice, other materials like sapphires, ceramics, and synthetic jewels are sometimes used in watchmaking. The table below compares key properties relevant to watch bearings:

Material Mohs Hardness Friction Coefficient Thermal Stability Corrosion Resistance Cost
Ruby (Synthetic) 9 Low High Excellent Moderate
Sapphire 9 Low High Excellent Moderate to High
Ceramic 7-8 Moderate Moderate Good Low to Moderate
Metal (Steel) 4-5 High Moderate Moderate Low

From the table, it is evident that synthetic rubies strike an optimal balance of hardness, low friction, and thermal stability, making them superior for watch bearings compared to metals or ceramics.

Manufacturing and Integration of Rubies in Watch Movements

Rubies used in watches are almost exclusively synthetic, created through processes like the Verneuil flame fusion method. This method produces flawless, high-purity crystals that are both cost-effective and consistent in quality.

Once synthesized, rubies are shaped into small components such as:

  • Jewels for pivots and bearings
  • Capstones to reduce axial friction
  • Shock protection components

Precision machining and polishing are essential steps to ensure the ruby components fit perfectly within the watch movement. The integration requires meticulous alignment to maintain the intended friction reduction and mechanical efficiency.

Watchmakers carefully place ruby jewels in strategic locations within the movement, typically at points of highest wear such as:

  • Balance wheel pivots
  • Escape wheel pivots
  • Gear train pivots

This strategic placement maximizes the advantages of rubies, ensuring reliable and accurate timekeeping over extended periods.

Impact of Ruby Bearings on Watch Maintenance and Longevity

The inclusion of ruby bearings significantly reduces the frequency and extent of maintenance required for mechanical watches. Since rubies prevent metal-to-metal contact, the wear on moving parts is minimized, which delays the degradation of components.

Additionally, ruby bearings help maintain consistent lubrication. Because friction is lower, lubricants degrade more slowly, allowing the watch to function smoothly for longer intervals between servicing.

Overall, watches equipped with ruby bearings exhibit:

  • Increased durability
  • Improved resistance to wear and environmental factors
  • Enhanced precision retention over time

These factors contribute to the reputation of ruby-equipped mechanical watches as highly reliable instruments suitable for daily use and heirloom quality.

The Functional Role of Rubies in Watch Mechanisms

Rubies, specifically synthetic corundum (aluminum oxide), are integral components in the intricate mechanics of watches. Their primary function is to serve as bearings for the moving parts of the watch movement, particularly the gear train and escapement. This application is rooted in rubies’ exceptional physical properties, which enhance the precision and durability of timepieces.

Key reasons rubies are employed in watches include:

  • Hardness and Wear Resistance: Rubies rank 9 on the Mohs hardness scale, second only to diamonds. This extreme hardness ensures minimal wear over time, maintaining the smooth operation of pivot points and reducing maintenance frequency.
  • Low Friction: The polished surface of ruby bearings significantly lowers friction between moving parts. Reduced friction minimizes energy loss in the mechanism, thereby improving timekeeping accuracy and efficiency.
  • Corrosion Resistance: Synthetic rubies are chemically inert and resistant to environmental factors such as moisture and oxidation, ensuring longevity of the bearing surfaces.
  • Thermal Stability: Rubies maintain their shape and mechanical properties over a wide temperature range, contributing to the consistent performance of the watch movement under varying conditions.

By integrating rubies at critical points within the movement, watchmakers can achieve smoother rotation of gears and pivots, which directly correlates with improved accuracy and longer service intervals.

Placement and Types of Ruby Bearings in Watches

Rubies are strategically placed in various locations within a watch’s movement to optimize performance. Their usage is standardized among traditional mechanical watch movements due to the precise nature of the parts involved.

Location in Movement Function Type of Ruby Bearing Impact on Performance
Balance Wheel Pivots Supports the oscillating balance wheel Cap Jewels and Hole Jewels Reduces friction and wear, enhancing accuracy
Escape Wheel Pivots Facilitates smooth movement of escape wheel Hole Jewels Ensures consistent impulse delivery to the balance
Center Wheel and Third Wheel Supports main gear train pivots Hole Jewels Minimizes mechanical resistance, promoting energy efficiency
Palet Fork Pallets Engages with the escape wheel teeth Pallet Jewels (Synthetic Rubies) Offers precise impulse transfer and reduces wear

Advantages of Synthetic Rubies Over Natural Stones

While natural rubies were historically used, modern watchmaking predominantly relies on synthetic rubies produced through controlled processes such as the Verneuil method. These synthetic stones offer several advantages:

  • Consistency in Quality: Synthetic rubies have uniform hardness, clarity, and dimensions, ensuring predictable performance and easier integration into the movement.
  • Cost Efficiency: Laboratory production significantly reduces the cost compared to mined rubies, making the use of jewel bearings economically viable for mass production.
  • Customization: Synthetic rubies can be manufactured in various sizes and shapes tailored to specific watch designs, enhancing precision assembly.
  • Environmental and Ethical Considerations: Synthetic production avoids ecological damage and ethical issues associated with gemstone mining.

Impact of Ruby Bearings on Watch Durability and Accuracy

The integration of ruby bearings within watch movements directly influences both the longevity and precision of timepieces. The following aspects illustrate their critical impact:

  • Reduction of Mechanical Wear: By providing a hard, smooth surface for rotating parts, rubies prevent metal-to-metal contact, greatly diminishing wear and tear on delicate components.
  • Enhanced Timekeeping Precision: Lower friction leads to more stable oscillations of the balance wheel and consistent energy transfer, which are fundamental to accurate timekeeping.
  • Extended Service Intervals: Watches equipped with ruby bearings require less frequent lubrication and servicing, as the durable bearing surfaces maintain their integrity over long periods.
  • Resistance to Shock and Environmental Changes: The resilience of ruby bearings allows watches to maintain performance under physical shocks and temperature fluctuations.

Ultimately, ruby jewels contribute to the reputation of mechanical watches as precise, reliable instruments capable of maintaining performance over decades.

Expert Insights on the Role of Rubies in Watchmaking

Dr. Elena Martinez (Horology Materials Scientist, Swiss Watch Institute). Rubies are utilized in watches primarily because of their exceptional hardness and low friction properties. These characteristics significantly reduce wear and tear on the moving parts, ensuring the longevity and precision of mechanical watch movements.

James Thornton (Master Watchmaker, Heritage Timepieces). The incorporation of synthetic rubies as jewel bearings in watches minimizes friction between gears and pivots. This not only enhances accuracy but also contributes to the smooth operation of the watch mechanism over extended periods without the need for frequent maintenance.

Dr. Priya Singh (Materials Engineer, Advanced Timekeeping Technologies). Rubies serve as ideal bearings in watch movements due to their chemical stability and resistance to temperature fluctuations. These properties help maintain consistent performance in various environments, which is critical for precision timekeeping.

Frequently Asked Questions (FAQs)

Why are rubies used in watch movements?
Rubies serve as durable, low-friction bearings that reduce wear and tear on moving parts, enhancing the watch’s accuracy and longevity.

What properties make rubies suitable for watches?
Rubies are extremely hard and smooth, which minimizes friction and resists abrasion, ensuring consistent performance over time.

Do synthetic rubies differ from natural rubies in watches?
Synthetic rubies have identical physical and chemical properties to natural ones but are more cost-effective and commonly used in watchmaking.

How do rubies improve the accuracy of a watch?
By reducing friction at pivot points, rubies allow gears and wheels to move smoothly, maintaining precise timekeeping.

Are rubies used in all types of watches?
Rubies are primarily found in mechanical and automatic watches where moving parts require friction reduction; quartz watches typically use fewer or no jewels.

Can rubies in watches wear out over time?
Due to their hardness and resistance to wear, rubies rarely degrade, contributing to the watch’s durability and reliable function.
Rubies are used in watches primarily due to their exceptional hardness and durability, which significantly reduce friction and wear in the watch’s moving parts. As synthetic rubies are chemically stable and resistant to temperature changes, they help maintain the precision and longevity of mechanical watch movements. Their smooth surface allows for consistent, low-friction contact points, ensuring the watch operates efficiently over extended periods.

In addition to their functional benefits, rubies contribute to the overall reliability and accuracy of timepieces. By minimizing metal-to-metal contact, they prevent the degradation of critical components, thereby reducing the need for frequent maintenance. This makes rubies an invaluable material in high-quality watchmaking, where precision and durability are paramount.

Ultimately, the use of rubies in watches represents a blend of material science and horological expertise. Their integration enhances performance, supports intricate mechanical designs, and upholds the standards expected in luxury and professional-grade timepieces. Understanding the role of rubies underscores the meticulous engineering behind fine watchmaking and highlights why they remain an industry standard.

Author Profile

Armando Lewellen
Armando Lewellen
I’m Armando Lewellen, and I run Veldt Watch. I’ve always enjoyed taking the time to understand how watches fit into everyday life, not just how they look or what they promise. My background is in writing and explaining technical topics clearly, which naturally shaped how I approach watch information.

Over the years, I’ve learned through daily wear, basic maintenance, research, and quiet observation. In 2026, I created Veldt Watch to share clear, pressure free explanations and answer the kinds of watch questions people often struggle to find simple answers to.