2017 SNC Optimized Preliminary Economic Assessment ("PEA")

The PEA, prepared by SNC-Lavalin (“SNC”), ”), integrates optimization work completed over the past six months and plans for direct-shipping material from the contract operator’s crushing and screening.  The updated PEA uses a new DSO pit constrained Measured resource of 2.5 million tonnes (“Mt”) grading 98.62% SiO2, Indicated resource of 5.3 Mt grading 98.62% SiO2 and an Inferred mineral resource of 2.1 Mt grading 98.66% SiO2 and was initially modeled with a 20-year mine life and 200,000 tonnes mined per year.. The PEA has a base case pre-tax net present value with a 10% discount rate (“NPV10%”) of $33.8 million and internal rate of return (“IRR”) of 157% and after tax NPV10% of $23.4 million and IRR of 132%.

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