I've heard of it, and if it doesn't break down quickly (within a year) then you should be fine, though you might consider adding a little organic compost or bark mulch, and/or some perlite.

Lucy, Thanks for your reply, sorry it took so long to get back to you. I am trying various combinations of soils to see which works the best. I tried pure zeolite, zeolite with shell grit, and potting mix with shell grit & zeolite. I am already using shell grit with potting mix to give some drainage to my soil.

I use a comercially available 'Bonsai Mix' as my normal potting mix.
Thx Ron

Oyster shells are not good. Proper chicken grit is decomposed granite, even though I understand that especially in the south oyster shells are used, but it's not good for plants.

I am not familiar with Zeolite, but use Isolite. It is a ceramic bead ( 2mm in size)or cyliners that has many small holes to retain moisture. I use approx. 20% Isolite, 35% sifted Pine Bark mulch and 45% #3 Builders Sand. Works very well on a wide variety of species.

Zeolite And Bonsai

Making the assumption that the original post was from an Australian, I will say that there are two commercial natural zeolite mines producing product in Australia of the clinoptilolite form that is commonly used in gardening around the world. I am involved with one of these so in the spirit of the forum I will not mention its name. A quick web search will find one of these two.
These Australian natural zeolite are harder than overseas deposits being in the mid 5âÂÂs on the mohs hardness scale out of 10 compared to 3âÂÂs and 4âÂÂs of those for example from Asia and USA. Typically being this hard when incorporated into a soil media this will last in its processed particle size for hundreds of years making it very suitable for this use.
We have bonsai clubs in New South Wales now using our product in a 1 to 3 mm particle size. This typically is included at 15% by weight into the potting mix.
Also include your other materials such as organic matter of various forms, manure, slow release fertiliser etc.
Zeolite this hard will give the potting media texture plus the usual thing zeolites offer in theaiding water retention, nutrient holding and hosting friendly soil microorganisms