Glossary · Mechanism
Jewel hole
A pierced synthetic or natural stone bearing that a pivot runs in.
Explanation
A jewel hole is the pierced stone — synthetic ruby in modern practice — in which a pivot runs. The hole's olive-shaped profile retains oil by capillary action. Cracked or chipped jewel holes increase friction and wear rapidly; they are pressed out and replaced with the correct size using a staking set or jewelling tool.
In the object catalogue
Catalogued objects whose own source record mentions “Jewel hole”. The quoted line shows where; it is the seller’s or museum’s wording, not independent verification.
