To solve the Treasure Box puzzle, you need to make various combinations of gems.

If you match a line of 4 gems of the same color, they form a Rocket, which will make all gems that are in the same row, vertical or horizontal, disappear.
A line of 5 gems of the same color will form a Rainbow Gem that will remove all gems of the same color as the gem with which it is combined.
If you make a T- or L-shaped combination of 5 gems of the same color you will get a special Bomb Gem. Bombs remove the gems around them.

You can also try combining special gems with one another. 2 different Rockets combined with one another will remove 2 entire rows of gems both horizontally and vertically. Combining a Rocket with a Bomb will create a Gem that removes 3 vertical and 3 horizontal rows. By combining 2 Bombs, you can remove more adjacent gems than you can with a single Bomb.
A combination of a Rainbow Gem and a Rocket will transform all gems of the same color as the matched Rocket into special tiles. Combining a Rainbow Gem with a Bomb will remove all gems of 2 random colors. Finally, a combination of 2 Rainbow Gems will remove all gems from the board.

There are 3 modes in this puzzle.
In Plates mode, you need to collect a certain number of plates from the board.
In Stargazer mode, you need to drop all of the celestial bodies (the Sun, the Moon, and Saturn) into jewelry boxes.
In Palette mode, you need to collect a certain number of gems of a certain color.

When solving this puzzle, you can use the Flying Time and Precise Arrow tools.
1. Flying Time gives you an additional 45 seconds to solve the puzzle.
2. Depending on the mode, the Precise Arrow removes a gem or activates a special tile as you prefer.