Yeah...Nope. You do understand what an antonym is, correct?
an·to·nym
[ˈan(t)əˌnim]
NOUN
linguistics
a word opposite in meaning to another (e.g., bad and good).

The key word being "OPPOSITE"

So Trump called them a "jewel" as in:

jew·el
[ˈjo͞oəl]
NOUN
a precious stone, typically a single crystal or a piece of a hard lustrous or translucent mineral, cut into shape with flat facets or smoothed and polished for use as an ornament.
synonyms: gem · gemstone · (precious) stone · brilliant · baguette · [more]
(jewels)
an ornament or piece of jewelry containing precious stones.
a hard precious stone used as a bearing in a watch, compass, or other device.
a very pleasing or valued person or thing; a very fine example:
"she was a jewel of a nurse"
synonyms: finest example/specimen · showpiece · [more]