Weight and dimensions of Hive game pieces?
It varies by edition. There are at least 4 versions of the game.

Version 1 was stickered wooden pieces; I do not know the size, but I suspect them to be rather close to the Bakelite. At least two different sticker sets were used by Gen42 games.

Version 2 was bakelite pieces, hexagons 37mm face to face, and 12mm thick. 

Version 3, "Hive Pocket" is also bakelite pieces, hexagons 24mm face to face, and 9.5mm thick.

Version 4, "Hive Carbon" is the same size pieces as the second version, but is black and white markings and tiles.

I lack a scale accurate enough to measure the mass.

Boardgamegeek.com has, on the hive entry, a table:

Item                         Hive    Hive Pocket
Tile Width Flat to Flat      38 mm   25 mm
Tile Height                  12 mm   10 mm
Weight of 26 tiles           600 g   200 g


On one of the images, it shows 38x12mm and 25x10mm for the bakelite