RE: [Demo notebook] Reference notebook: corrections and recurring beginner questions · RWI-07820

Case 41 — Crystal types: sapphire, mineral and acrylic trade-offs for daily wear · source wording exercise

Spec sheets list sapphire, mineral or acrylic crystals, and opinions in threads are very strong. For a daily-wear watch, what are the real trade-offs, and is an anti-reflective coating worth paying for?

Review focus: source wording. Retain the source wording beside any paraphrase. Use the original answer fragment “Sapphire is very hard to scratch but can chip or crack…” as the discussion anchor; no new event or result is supplied.

Exercise RWI-07820/41: address this question within its stated limits.