At 350 mA, 70-80 lumens, with forward voltage drop of 3.2-3.4 volts.
(100 lumens and more at 100 mA at similar or slightly lower voltage are available from Mouser, Digi-Key and Future, but at higher prices)
This means 70-80 lumens at 1.12-1.19 watts. Yes, it is common practice to call such LEDs "1-watt LEDs".
This means 59-71.4 lumens/watt. This is not counting losses in whatever is used to control the current through the LEDs.
Color temperature is stated as 6000-6500 K - sounds to me like a usual icy color white LED. Color rendering index is probably usual of LEDs of such color and efficiency, which has usually been said to be 70, maybe 75. (I have seen a few closer to 80.)
In comparison, home lighting usually "wants" color temperature in the range of 2700-3500 K and color rendering index at least 80, preferably past 90. Getting color temperature lower than 4,000's to 5,000 K and increasing CRI means less lumens out per watt in.