Some more detail about this Orb from The Crown Jewels 1998 follows.
The clusters and jewels were changed often from one reign to the next. 
In 1930 Garrard’s supplied 266 cultured pearls to replace imitation pearls bordering those bands known as the zone and arc.
“The monde, rising from a circle of eight roses on top of the arc, is a pyramidal amethyst cut with vertical stepped facets bound by four gold straps with ribbed centres.”
For the cross on top “A table-cut sapphire with clipped corners in a gold mount is set at the intersection on one side of the cross, an emerald on the reverse.”
“The inside of the Orb is inscribed with the names of goldsmiths executing repairs in 1838, 1842, 1876 and 1937.”
“The Orb lost in 1649 was very considerably smaller than the version made in 1661, since it weighed only 17¼ oz” [compared with 42oz 7dwt (1.32kg)]

Queen Elizabeth II carrying this Orb and the Sceptre with Cross