The confirmation of lithium and higher-grade boric acid is significant for 5E Advanced Materials as it directly relates to the company's core mining operations and future product offerings. This news is likely to be viewed positively by investors, as it suggests the potential for increased resource valuation and revenue from these critical materials. Given the current demand for lithium in various industries, especially in electric vehicle batteries, this could lead to increased investor interest and a potential rise in stock price in the short term.