The word "Jade", like the word "Onyx", is commonly used throught the gemstone trade to mean several completely different kinds of stone. It is used to mean 1) Jadeite: a silicate of sodium and aluminium in the pyroxene group of minerals, a completely different stone called 2) Nephrite: a silicate of calcium and magnesium in the amphibole group of minerals and 3) False/Pseudo Jade: ANY stone of ANY color that the seller THINKS might be jadeite or nephrite and they don't really knowwhat it is but no one is ever gonna check and there are zero consequences and many benefits to labeling something as jade. An awful lot of the pseudo-jade out there are various stones from the Serpentine subgroup (part of the kaolinite-serpentine group in the category of phyllosilicates) which are greenish, brownish, or spotted minerals commonly found in serpentinite.
In my 50 years in the gemstone and jewelry trade I've never heard of "Old Topaz Jade" before. I did a google search for that term and looked at the first 5 pages of results. I also looked for it on mindat and gemdat and to see what was being sold under that name on eBay and Etsy. From what I can tell it's a new trade name and it could literally be anything. Some of the pics I saw labeled as "Topz Jade" looked like chalcedony and some were clearly banded calcite! "Old" is a marketing term and "Topaz" is simply an upscale marketing term reference to color. I can definitely NOT say for sure what it is based on a picture but I would bet money that it falls into the "pseudo jade" group and it is either a flavor of chalcedony or serpentinite. A hardness check by someone familiar with both materials could tell more.
Here are the images that show up in a Google Image Search for Topaz Jade...
