Custer Feldspar

Custer Feldspar

Regular price
$2.80
Sale price
$2.80


This is one of the main feldspars used in the ceramic industry in North America. It is used in industries such as abrasives, sanitary ware, floor and wall tile, dinnerware, pottery, and electrical porcelain. It is a ceramic grade, high potash feldspar and is available in crude, 200, 325 mesh and chip form.

Since 2012 we have been getting independent reports of a reduction in the potash content (below that stated on the data sheet). Traditionally Pacer, the manufacturer, has reported it as around 10% (as is shown in the chemistry given here, and from their online data sheet). However Ron Roy claims that, from his independent analysis of specimens over time, around the year 2000 the K2O content dropped to about 7.5 (with no accompanying change in the Na2O). Pacer disputes this. The chemical analyses they provide with individual shipments of material continue to report K2O, Na2O and Fe2O3 levels at quite similar to those stated on their data sheet. Additionally, they have a page on their website named "Clarification of Custer Feldspar Chemical Composition Data" in which they claim their analysis is, and has been, accurate.

As with any feldspar, production users should be vigilant to do sieve analysis testing to spot any iron bearing particles in the plus 100 mesh range.