First Class Metals Confirms High-Grade Lithium and Rubidium in Grab Samples at Zigzag Project

First Class Metals PLC (LSE: FCM) has announced outstanding grab sample results from its Zigzag Project in Ontario, Canada. While the project is being advanced primarily as a lithium pegmatite asset, assays have also confirmed very high rubidium grades, alongside tantalum, caesium, and gallium—positioning Zigzag as a critical multi-metal discovery opportunity.

Key Results from Initial Sampling

• Lithium (Li₂O): 19 samples reported >1% Li₂O, with a further 3 samples >0.5% Li₂O. Best spodumene-rich samples returned 2.97% and 2.75% Li₂O, confirming a continuous strike >350m that remains open in both directions.

• Rubidium (Rb): 9 samples reported >1,000 ppm Rb, including a peak of 3,800 ppm Rb (0.38% Rb₂O). Consistently elevated values across the main zone suggest rubidium enrichment as a significant economic credit.

• Tantalum & Other Critical Metals: 6 samples >250 ppm tantalum, with a peak of 724 ppm Ta. Anomalous caesium also present, adding further critical mineral value.

Rubidium – A Rare Critical Metal

Rubidium is designated a critical technology metal by both the USGS and Government of Canada due to its importance in:

• Electronics & semiconductors

• Specialised glass & fibre optics

• Military and aerospace technologies

With global supply dominated by China and prices reported above US$3,100/oz, new rubidium exploration projects like Zigzag are emerging as strategic opportunities for investors.

Exploration Upside at Zigzag

• Continuous lithium-rubidium trend: over 350m of strike already defined, open in both directions and at depth.

• Channel sampling completed: over 80 samples cut across ~60m, results pending.

• Prospecting ongoing: further work underway on both the main pegmatite zone and subparallel structures, which could host additional lithium and rubidium mineralisation.

CEO Comment

Marc J. Sale, CEO of First Class Metals, said:

“The excellent grab sample results have proved up a core lithium-bearing zone at Zigzag that remains open. The presence of rubidium alongside lithium and tantalum adds a valuable new dimension to this project’s growth potential.”

Why Zigzag is Strategic

The Zigzag Project is rapidly emerging as more than just a lithium play. With high-grade rubidium assays (up to 3,800 ppm) and consistent tantalum credits, the project is uniquely positioned to become a dual lithium-rubidium critical metals asset in Ontario’s pegmatite-rich Seymour-Falcon corridor.

This makes First Class Metals one of the very few rubidium exploration companies outside of China, giving investors direct exposure to a scarce and valuable technology metal.