Diamond longsword

The diamond longsword is a level 65 longsword that requires 65 Attack and 70 Slayer to wield. It is widely considered to be one of the best diamond weapons available, since it has two powerful types of attack styles. There two ways of obtaining the sword: either buying it from the Grand Exchange or receiving it as a rare drop from Metallic experiments. Many metal dragons have a strong weakness to diamond weapons as well as stab attack, giving even more uses of the diamond longsword because of its high strength and stab attack bonus. It also comes with a special attack.

Special attack
The special attack of Diamond longsword is called Glasscut, which causes the player to do a slow but powerful stab in a similar position as Vesta's longsword. The special attack has an increased strength and is fairly accurate. Once hit, 10% of the damage dealt will drain the opponent's accuracy, damage output or defence randomly, alternatively if used on a monster, it decreases its Melee defence.

History and market
Diamond weapons were released alongside the 120 Slayer expansion. During its release, Diamond longswords price started at 5,3 million, but steadily rose to a peak of 11 million coins because of it's bonuses as well as being a weakness to metal dragons, however the Diamond twinhammers never changed in price. After a while, the longsword increased up to 29 million, which was worth more than a Bandos godsword. A silent update soon caused 60% damage reduction in PvP worlds, which soon angered a lot of Pkers because it cannot completely be used as a "K.O." as it was before. This caused the price to drop down to 2,500,000, a hidden update soon changed this. The update caused Diamond longsword to deal 10% more damage while fighting metal dragons, which increased its price to upwards of 19,000,000, where it stabilised for the time. After Evolution of Combat, the prices of diamond longsword crashed, due to having its special attack and effectiveness against dragons removed and becoming overall less effective weapon than cheaper, higher-level weapons such as abyssal whip. Eventually, the prices of diamond longsword stabilized little bit above its High Alchemy price.

Trivia

 * The diamond longsword looks very similar to Vesta's longsword with a similar special attack.
 * The diamond longsword is extremely commonly seen by high-levelled players who are slaying dragonite dragons.
 * Despite having lower bonuses than diamond twinhammers, they were much more expensive, due to their better utility.
 * The drop-rate is 1/1510 from Metallic experiments.