Preliminary Metallurgical Tests Result in over 80% Vanadium Extraction from Cornerstone Metals Inc.'s Carlin Vanadium Project

Vancouver, British Columbia--(Newsfile Corp. - May 29, 2018) - Cornerstone Metals Inc. (TSXV: CCC) (OTCQB: CCCCF) (FSE: 1PY) ("Cornerstone" or the "Company") is pleased to announce preliminary results of metallurgical test work being conducted on its Carlin Vanadium Project in Nevada. The initial pressure leaching tests have achieved vanadium extraction levels of between 80.2% and 83.6%.

"The Company is thrilled with these preliminary results, which signal a major technical breakthrough for this project", said Cornerstone President and Chief Executive Officer Paul Cowley, "guided by expertise of Cornerstone's metallurgists and Sherritt Technologies, an industry recognized engineering and research group with their in-house lab. Regardless of these positive results, we are continuing test work to improve upon the overall vanadium extraction from the current 80.2% to 83.6% to higher values."

Test work is being conducted on a sample composite generated from an 18.9 metre drill core intercept from the Company's recent diamond drilling verification program. Metallurgical test work will continue with the aim of developing a conceptual flowsheet.

Metallurgical test work is being conducted by Sherritt Technologies in Fort Saskatchewan, Alberta, the leader in the development and commercialization of pressure hydrometallurgical processes. Sherritt is a one-stop shop that has a proven track record of developing projects from concept-to-operation with a skilled and experienced team, including process and equipment specialists.

The Carlin Vanadium deposit is considered one of the largest, highest grade primary vanadium deposits in North America (USGS Professional Paper 1802 Critical Mineral Resources of the United States-Economic and Environmental Geology and Prospects for Future Supply dated December 18, 2017).

Vanadium's Growing Importance for Steel Manufacturing and the Energy Sector

Vanadium is growing in importance for key industrial manufacturing sectors most notably steel and renewable energy. Today, more than 85 percent of the world's vanadium is used in steel manufacturing applications. Its importance to the energy sector is also growing rapidly with more than 10 percent of vanadium production used in energy storage where its substantial cost and performance benefits make it an alternative choice to lithium ion in several areas. Vanadium pentoxide flake prices have risen over the last 2.5 years from under US$3/lb to US$13.90/lb today.

About Cornerstone Metals Inc.

Cornerstone Metals has an option to earn a 100% interest in the Carlin Vanadium Project, located in Elko County 22km by road (14 miles) from the town of Carlin, Nevada. The project is comprised of 72 contiguous unpatented mineral claims totaling 461 hectares (1,140 acres). The Carlin Vanadium Project hosts the Carlin Vanadium Deposit which is flat to shallow dipping and at shallow depths, commonly between 0-60m (0-200 ft) below surface.

ON BEHALF OF CORNERSTONE METALS INC.

per: "Paul Cowley"
CEO & President
(604) 340-7711
pcowley@cornerstonemetals.ca

Technical disclosure in this news release has been reviewed and approved by Paul Cowley, P.Geo., a Qualified Person as defined by National Instrument 43-101, and President and CEO of the Company.

Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in policies of the TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.

Forward-looking information

Certain statements in this news release constitute "forward-looking" statements. These statements relate to future events or the Company's future performance and include the Company's ability to meet the conditions required to exercise in full its option to acquire the Carlin Vanadium project and with respect to current and planned drill programs, the results of exploration programs, metallurgical test work, and changes in mineral resources. All such statements involve substantial known and unknown risks, uncertainties and other factors which may cause the actual results to vary from those expressed or implied by such forward-looking statements. Forward-looking statements involve significant risks and uncertainties, they should not be read as guarantees of future performance or results, and they will not necessarily be accurate indications of whether or not such results will be achieved. Actual results could differ materially from those anticipated due to a number of factors and risks. Although the forward-looking statements contained in this news release are based upon what management of the Company believes are reasonable assumptions on the date of this news release, the Company cannot assure investors that actual results will be consistent with these forward-looking statements. The forward-looking statements contained in this press release are made as of the date hereof and the Company disclaims any intention or obligation to update or revise any forward-looking statements whether as a result of new information, future events or otherwise, except as required under applicable securities regulations.