In this RuneScape 3 guide, we will explore how to make Runescape gold with Limestone. In this technique, which I recently discovered and tested for validity, Limestone bricks are purchased and noted, and later converted into wall segments. 

• Gold-Making Potential: Your results may vary
• Part One: Collecting Stone
• Part Two: Making the walls
• Final Thoughts

As this method is not particularly AFK-friendly, requiring attention every 16 seconds or so, it may be a little repetitive and annoying; however, wall segments are in high demand due to the Four and Three quest line.

↖ Gold-Making Potential: Your results may vary

Requirements: Barrows Wars Retreat teleport, Prifddinas access, Magic Note Paper, and a moderate amount of time and clicking effort.

↖ Part One: Collecting Stone

• Preparation: Bring around 30K in cash and Magic Note Paper.
• Location: Use the Wars Retreat teleport and set a portal to the Barrows Brothers. Then, head west to the General Store.
• Purchasing: Right-click the storekeeper and select the Trade Builder Store option. Buy all the Limestone bricks available and note them using Magic Note Paper. Repeat this process until you have about 1,000 noted stones.
• Efficiency Tip: Position the shop interface close to your inventory for faster transactions. This part typically takes about 5 minutes, depending on your clicking speed.
• Additional Location: Visit the southwest of Prifddinas and repeat the process. Note that the quantity of bricks may be less here.

In this step, you may decide to cash out your profits by selling the Limestone bricks as they are for a quick profit.

This part of the method can yield approximately 1.2 million GP for 7 minutes of work.

↖ Part Two: Making the walls

• Location: Go to the Fort Four and Three bank.
• Preparation: Set the Limestone brick as a bank preset for quick access.
• Process: Alternate between the bank and the stone cutter to make wall segments. This can be monotonous, so feel free to watch a video or engage in another activity to pass the time.
• Repeat: Continue this process until all Limestone bricks are converted into wall segments.
• Earnings Analysis: The cost of making the stone walls totals approximately 843K GP, with a profit of around 3.4 million GP.

↖ Final Thoughts

Just collecting stones nets you 1.2 million GP for 7 minutes of effort, while converting them into walls adds an additional 2.2 million GP for 17 minutes of work. Depending on your perspective, this could be a worthwhile venture. Alternatively, for a more laid-back approach, consider AFK methods like archaeology.