Part 4 Minbrie Evaluation, page-3

Great question, Evan. The density factor (we used 3.0 t/m³) is critical in converting the physical volume of rock into total tonnage. Here’s how it works: once you estimate the size of the mineralised body (length × width × depth), you get a volume in cubic metres. But volume alone doesn’t tell you how much metal is in the ground you need to multiply it by density to get tonnes of rock. For example, 1,000,000 m³ × 3.0 t/m³ = 3,000,000 tonnes. From there, you apply metal grades (e.g. 1% Cu = 10 kg Cu per tonne of rock) to calculate total contained metal. So without the density factor, you can’t get to tonnage and without tonnage, there’s no in-situ value. That’s why it’s baked into every mining model from day one, and yes, the 3.0 t/m³ density factor I used is both fair and actually conservative. In massive sulphide systems like Minbrie which contain copper, lead, zinc, silver, and other heavy metals typical rock densities range from 2.9 to 4.5 t/m³ depending on sulphide content. Using 3.0 is common in early-stage modelling and aligns with industry standards. For reference: Golden Grove (WA) uses ~3.1–3.4, Rosebery (Tas) uses 3.0–3.2, CSA Cobar sits around 3.2 3.3 for high-grade zones, and Mt Isa sometimes exceeds that in denser ore. So yes, 3.0 is fair especially since no SG (specific gravity) testing has been publicly released yet. I prefer to stay conservative until that data confirms otherwise. Using 2.6 or 2.7 would understate the in-situ potential, while using 3.3 or 3.4 would inflate it. Hope that helps clarify and I hope you guys are slowly learning and getting the real picture of potential here. Steve