9" cobalt Warwick vase. Imperial also made this vase but not in cobalt. According to Tom Felt, "There is no documentation that Imperial ever made this vase in any colors other than heather (amethyst) or verde (green). The HCA's publication on Heisey by Imperial was pretty thoroughly researched at a time when they had access to records at Imperial, so I'm 99% certain your vase is Heisey cobalt. (The other 1% is that Imperial could have done a few trial pieces in colors that cannot be documented, so that can't be ruled out.) The absence of the Diamond H is not particularly meaningful, since it had to be frequently refreshed in the mould or it would wear away and become invisible."
Bredehoft's Encyclopedia of Heisey Glass 1925-1938 states on p.119: "Imperial Reissues:Although not listed or advertised in their regular line, Imperial made the 1-light candlestick, and the 7" vase in heather and verde."