At some point between the courier's signature and the proposal, you will briefly own the most valuable small object of your life so far, one that fits in a pocket, attracts attention, and loves to slide off cold fingers into moving water. Insurance is how that sentence stays funny.
What coverage costs and covers
Specialty jewelry insurance generally runs in the neighborhood of one to two percent of the ring's value per year, a rounding error against the purchase. Good policies cover loss, theft, damage, and the quietly common catastrophe of a stone departing its prongs. Renters and homeowners policies can carry the ring instead through a scheduled rider, often cheaply, though limits and deductibles want reading before you assume anything.
The grading certificate doubles as the insurance exhibit. Keep it with the documents you do not lose.
The small print that matters
Insurers want the certificate or a recent appraisal, so the paperwork from a reputable seller does double duty. Ask three questions before binding: replacement in cash or through their jeweler, how deductibles work on partial losses like a chipped stone, and whether the ring is covered in transit and abroad. The transit clause matters the week it ships and every vacation thereafter.
When to bind it
The correct date is the day the ring arrives, not the day of the proposal. The interval between the two is precisely when the ring lives in sock drawers, glove boxes, and jacket pockets, which is to say, in its statistical prime for disappearing.
The short of it: one to two percent a year, bound the day it arrives, with the certificate filed where the passports live.