Watch Glossary

Radioactive element formerly used in watch lume, less hazardous than radium but still radioactive

Physical Vapor Deposition; durable coating applied to steel for black or colored finish

Vintage luminous materials containing radioactive elements like radium or tritium for continuous glow

Radioactive luminous paint used pre-1960s; highly collectible but hazardous.

Observable color shift in radioactive luminous material from original cream to butterscotch or brown.

Luminous coating sometimes applied to the watch rehaut ring near the dial edge

Professional restoration service applying new luminous material to vintage watch dials and hands

Durable elastomer material for watch bracelets, popular in diving and sport watches

Dial construction with luminous layer between transparent sapphire and dial base for enhanced lume

Transparent synthetic sapphire crystal used for case construction, offering exceptional clarity and hardness.

Synthetic sapphire used for watch crystals; extremely hard and scratch-resistant

Rolex's exclusive rose gold alloy with improved resistance to color fading and corrosion over time.

Seiko's proprietary hardened crystal material used in Prospex professional dive watches for scratch resistance.

Solid metal links connecting band to case, versus hollow bracelet end links.

Corrosion-resistant iron alloy containing chromium and nickel, standard watchcase material

High-grade corrosion-resistant steel alloy with superior polishing and durability characteristics.

Medical-grade stainless steel with low carbon content, highly corrosion-resistant

Specification measuring balance between visible gemstone and metal in setting.

Lightweight, hypoallergenic metal alloy offering excellent strength and corrosion resistance

Medical-grade titanium alloy offering superior strength-to-weight ratio and hypoallergenic properties.

Dial coated with tritium, a radioactive hydrogen isotope providing continuous glow without light exposure

Measurement of remaining luminosity in tritium-based lume indicating age authenticity.

Radioactive luminous material used in vintage watches, glows without recharging.

Sealed glass or metal tube filled with tritium gas used for constant watch dial luminescence

Original luminous coatings from older watch era, often radioactive and subject to patination

Pure ceramic material used for watch cases and components, offering extreme scratch and heat resistance.

Neutral luminous material that glows white or pale, used in some contemporary watch designs

Super-LumiNova formulation known for bright green glow and reliable luminescence performance