Gemstone Vineyard was founded in the mid-1990s by Paul and Suzie Frank. The first releases were in 1997. When the Franks wanted to retire a decade later Michael Marks, a Silicon Valley technology executive, and his wife Carole bought the estate. Today the 17-acre estate makes Bordeaux-style wines. The winemaker is Philippe Melka, a native of Bordeaux who worked for Chateau Petrus and Haut-Brion and later at wineries in Australia and Italy. About 1,400 cases are produced annually. Gemstone makes Cabernet Sauvignon, Merlot-based blends and Chardonnay.