Gutenberg 5.3 delivers a number of new blocks. These will soon be catalogued in blocks.wp-a2z.org. And when the time comes, when they have been merged into WordPress, they’ll be catalogued in core.wp-a2z.org.
Core
core/calendar
Calendar
A calendar of your site’s posts.
widgets
posts,archive
core/legacy-widget
Legacy Widget (Experimental)
Display a legacy widget.
widgets
core/rss
RSS
Display entries from any RSS or Atom feed.
widgets
Atom,Feed
core/search
Search
Help visitors find your content.
widgets
find
core/tag-cloud
Tag Cloud
A cloud of your most used tags.
widgets
Core embed
core-embed/amazon-kindle
Amazon Kindle
Embed Amazon Kindle content.
embed
eBook