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

	Grade	Damage	Cooldown	Range	Description
	Chipped	4 - 4	32	5.5	Attacks up to three targets.
	Flawed	8 - 8	40	5.5	Attacks up to three targets.
	Normal	14 - 14	40	5.5	Attacks up to four targets.
	Flawless	25 - 25	40	5.5	Attacks up to four targets.
	Perfect	75 - 75	40	6.6	Attacks up to five targets.
	Great	250 - 250	40	7.7	Attacks up to seven targets.