Opalex Covered Jar Made in France

This little vitrified cream color opaque glass Opalex jar looks very much like the custard glass from the 40's. The inside of the lid says Opalex Made in France, as does the bottom of the jar. The number 15 is in the middle of the bottom. The jar measures 3.5" wide by 2.5" tall. The jar and lid weigh a substantial 12 oz so this jar should be around for many years. The jar is in excellent condition with no chips, cracks or crazing. There is variation in the glass with a lighter ribbon of color in both the lid and the base, not to be confused with a crack. On close examination you can see a loop of this lighter ribbon of color.