1) Arthur Rostron
The letters “arthur” are hidden in the ruby on the crown.
TORSNOR is faintly visible in the shadow under the yolk.
TORSNOR is an Anagram of Rostron.
3) Ammonite
The nacreous layer of the aragonite fossil shells of some extinct ammonites forms an iridescent material called ammolite.
Ammolite formula:
CaCO3 aragonite polymorph, with minor amounts of calcite, pyrite, silica, and other impurities
4) W_ S_ L_ Banner
Unsolved? White Star Line → Titanic → Ice → CaCO3