Classic Mode Scoring
A single 3-gem match is worth 50 points.
A 4-gem match (which creates a Flame Gem) is worth 100 points. Detonating a Flame Gem earns 50 points for making the match, 20 points for detonating the Flame Gem, and 20 points per gem destroyed (including the Flame Gem).
A 5-gem match (which creates a Hypercube) is worth 500 points. Detonating a Hypercube earns 50 points for the detonation plus 50 points per gem destroyed.
A T- or L-shaped match (which creates a Star Gem) is worth 150 points. Detonating a Star Gem earns 50 points for the detonation plus 50 points per gem destroyed.
When you make two simultaneous matches, you are awarded 50 per match plus a 50 point bonus, or 150 points in total.
Cascades earn 50 bonus points apiece, increasing by 50 points for each additional cascade. So, a match that creates two cascades would score 50 points (for the 1st match), plus 100 points (50 points for the 2nd match plus 50 cascade points), plus 150 points (50 points for the 3rd match plus 100 cascade points), or 300 points total.
In Classic Mode, all base score values are multiplied by the level number. So, on level 1, points are earned at the base values listed above. On level 2, points are earned at twice the base levels. At level 3, points accrue at three times the base values, and so on.
Speed Mode Scoring
Speed Mode features all basic scoring described above multiplied by 5, with one exception: creating Hypercubes scores the same in all modes, 500 points.
In addition, the base value of the Speed Bonus starts at 200 points and is added to the score for a match. Speed Bonuses increase by 100 points each match as long as the Speed Bonus is maintained to a maximum of 1000 points.
The base value of matching a Time Extender is 250 points.
All these values are then multiplied by the current Multiplier value.