Gem Tower Defence, as in the original Flash game, features eight basic gems, all of which are available in six tiers. This page presents the specification of each gem.
The gems' graphics are shown in PNG format in the tables below; be aware that the game uses scalable (SVG) versions of these images.
Note 1: Range is counted in grid tiles. One tile equals 13 px of the original game's count.
Note 2: Cooldown is counted in game ticks. The game is set to run at 40 ticks per second, therefore 1 tick = 25 ms.
Amethyst
| Grade | Damage | Cooldown | Range | Description |
---|
 | Chipped | 9 - 13 | 32 | 11.0 | Attacks air only. |
 | Flawed | 18 - 25 | 40 | 12.375 | Attacks air only. |
 | Normal | 30 - 40 | 40 | 13.75 | Attacks air only. |
 | Flawless | 60 - 75 | 40 | 14.3 | Attacks air only. |
 | Perfect | 140 - 150 | 40 | 16.5 | Attacks air only. |
 | Great | 350 - 400 | 40 | 18.15 | Attacks air only. |
Aquamarine
| Grade | Damage | Cooldown | Range | Description |
---|
 | Chipped | 6 - 8 | 20 | 3.85 | Fast attack speed. |
 | Flawed | 12 - 15 | 20 | 4.015 | Fast attack speed. |
 | Normal | 24 - 30 | 20 | 4.18 | Fast attack speed. |
 | Flawless | 48 - 55 | 20 | 4.4 | Fast attack speed. |
 | Perfect | 100 - 120 | 20 | 6.05 | Fast attack speed. |
 | Great | 280 - 280 | 20 | 6.6 | Fast attack speed. |
Diamond
| Grade | Damage | Cooldown | Range | Description |
---|
 | Chipped | 8 - 12 | 32 | 5.5 | Attacks ground only and has 25% chance to deal 2× damage. |
 | Flawed | 16 - 18 | 40 | 6.05 | Attacks ground only and has 25% chance to deal 2× damage. |
 | Normal | 30 - 37 | 40 | 6.6 | Attacks ground only and has 25% chance to deal 2× damage. |
 | Flawless | 58 - 65 | 40 | 7.15 | Attacks ground only and has 25% chance to deal 2× damage. |
 | Perfect | 140 - 150 | 40 | 8.25 | Attacks ground only and has 25% chance to deal 2× damage. |
 | Great | 300 - 350 | 40 | 9.35 | Attacks ground only and has 25% chance to deal 5× damage. |
Emerald
| Grade | Damage | Cooldown | Range | Description |
---|
 | Chipped | 4 - 7 | 32 | 5.5 | Deals a poison attack that does 2 damage per second, and slows the target enemy's movement by 15%. Lasts 3 seconds. |
 | Flawed | 10 - 13 | 40 | 6.05 | Deals a poison attack that does 3 damage per second, and slows the target enemy's movement by 20%. Lasts 4 seconds. |
 | Normal | 15 - 25 | 40 | 6.6 | Deals a poison attack that does 5 damage per second, and slows the target enemy's movement by 25%. Lasts 5 seconds. |
 | Flawless | 30 - 38 | 40 | 7.7 | Deals a poison attack that does 8 damage per second, and slows the target enemy's movement by 30%. Lasts 6 seconds. |
 | Perfect | 80 - 90 | 40 | 9.9 | Deals a poison attack that does 16 damage per second, and slows the target enemy's movement by 50%. Lasts 8 seconds. |
 | Great | 250 - 250 | 40 | 9.9 | Deals a poison attack that does 50 damage per second, and slows the target enemy's movement by 50%. Lasts 30 seconds. |
Opal
| Grade | Damage | Cooldown | Range | Description |
---|
 | Chipped | 5 - 5 | 32 | 6.6 | Gives an aura to other gems within 6.6 range which increases their attack speeds by 10%. |
 | Flawed | 10 - 10 | 40 | 7.7 | Gives an aura to other gems within 7.7 range which increases their attack speeds by 15%. |
 | Normal | 20 - 20 | 40 | 8.8 | Gives an aura to other gems within 8.8 range which increases their attack speeds by 20%. |
 | Flawless | 40 - 40 | 40 | 9.9 | Gives an aura to other gems within 9.9 range which increases their attack speeds by 25%. |
 | Perfect | 85 - 85 | 40 | 11.0 | Gives an aura to other gems within 11.0 range which increases their attack speeds by 35%. |
 | Great | 180 - 180 | 40 | 16.5 | Gives an aura to other gems within 16.5 range which increases their attack speeds by 50%. |
Ruby
| Grade | Damage | Cooldown | Range | Description |
---|
 | Chipped | 8 - 9 | 40 | 8.8 | Attacks cause splash damage. |
 | Flawed | 13 - 16 | 40 | 8.8 | Attacks cause splash damage. |
 | Normal | 20 - 25 | 40 | 8.8 | Attacks cause splash damage. |
 | Flawless | 38 - 45 | 40 | 8.8 | Attacks cause splash damage. |
 | Perfect | 80 - 104 | 40 | 9.9 | Attacks cause splash damage. |
 | Great | 140 - 140 | 20 | 9.9 | Attacks cause splash damage. Attacks up to three targets. |
Sapphire
| Grade | Damage | Cooldown | Range | Description |
---|
 | Chipped | 5 - 8 | 32 | 5.5 | Attacks will slow target's movement speed by 20% for 5 seconds. |
 | Flawed | 10 - 13 | 40 | 8.25 | Attacks will slow target's movement speed by 20% for 5 seconds. |
 | Normal | 16 - 21 | 40 | 8.8 | Attacks will slow target's movement speed by 20% for 5 seconds. |
 | Flawless | 30 - 40 | 40 | 9.35 | Attacks will slow target's movement speed by 20% for 5 seconds. |
 | Perfect | 60 - 75 | 40 | 15.4 | Attacks will slow target's movement speed by 20% for 5 seconds. |
 | Great | 200 - 200 | 40 | 22.0 | Attacks will slow target's movement speed by 20% for 5 seconds. |
Topaz