Understanding Potash Feldspar — The Baseline

Potash feldspar — also known as potassium feldspar, K-feldspar, or K-spar — is a naturally occurring aluminosilicate mineral rich in potassium oxide (K₂O). It is one of the most important fluxing raw materials in the ceramic and glass industries worldwide, forming 20–35% of most tile bodies and 15–30% of porcelain and sanitaryware slips.

The chemical formula of potash feldspar is KAlSi₃O₈ (orthoclase or microcline). In its purest form, it is colourless to white. However, natural geological deposits contain varying amounts of iron oxide (Fe₂O₃), titanium oxide (TiO₂), and other trace minerals — and it is these impurities, particularly iron oxide (Fe₂O₃), that create the visual and functional difference between pink and white potash feldspar.

What Is Pink Potash Feldspar?

Pink potash feldspar gets its characteristic pinkish-cream to salmon colour from a higher concentration of iron oxide (Fe₂O₃) within the mineral crystal structure. The iron substitutes into the feldspar lattice and causes a reddish-pink hue that ranges from pale cream-pink to deep salmon depending on the deposit and beneficiation level.

Pink potash feldspar is typically sourced from deposits where full iron-removal beneficiation has not been applied, or where the geology naturally produces higher-iron K-spar. It is not a lower-quality mineral — it simply has a different chemical profile that makes it ideal for specific industries where whiteness is not a primary requirement.

Key Characteristics of Pink Potash Feldspar

• Fe₂O₃ content: typically 0.15% to 0.50% — higher iron gives the pink/cream colour
• K₂O content: 10–13% — same strong flux performance as white grade
• Fired colour: cream to off-white with warm undertone — acceptable for dark or coloured ceramic bodies
• L* whiteness: typically 75–85 (lower than white grade)
• Price: generally more economical than white potash feldspar
• Vitrification: excellent — K₂O drives clean, high-temperature vitrification
• Applications: floor tiles, rustic tiles, vitrified tile bodies (non-white), industrial ceramics, welding electrode coatings, refractory, abrasives

What Is White Potash Feldspar?

White potash feldspar is processed through a more rigorous beneficiation process — including magnetic separation, flotation, and careful mine selection — to reduce iron oxide (Fe₂O₃) and titanium oxide (TiO₂) to the lowest possible levels. The result is a bright white to creamy-white powder that fires to a snow-white or bright-white colour in the ceramic kiln.

White potash feldspar is the premium grade — the choice for any manufacturer where the whiteness, brightness, and purity of the final fired product is a competitive requirement. This includes porcelain tile, vitrified GVT/PGVT tiles, bone china, sanitaryware, wall tiles, and transparent glaze formulations.

Key Characteristics of White Potash Feldspar

• Fe₂O₃ content: below 0.10% — ultra-low iron for maximum whiteness
• TiO₂ content: below 0.05% — low titanium for colour purity
• K₂O content: 10–13% — same strong flux as pink grade
• Fired colour: snow white to bright white — consistent L* 88–94
• L* whiteness: 88–94 (high whiteness benchmark)
• Button test: clean, smooth, white, pinhole-free melt
• Applications: vitrified tiles, porcelain tile, bone china, fine porcelain, sanitaryware, wall tiles, glaze, frit, glass

Pink vs White Potash Feldspar — Full Technical Comparison

Which Industries Use Pink Potash Feldspar?

Pink potash feldspar is an excellent, cost-effective mineral for industries where the colour of the fired body is either dark, covered by surface treatments, or where colour consistency is not a whiteness-driven specification.

Which Industries Use White Potash Feldspar?

White potash feldspar is the essential choice for any manufacturer where the whiteness, brightness, and colour purity of the fired product is a market requirement or quality standard.

Which Grade Should You Choose? — Decision Guide

Use this quick reference table to identify the right grade for your specific application:

Button Test — Pink vs White Potash Feldspar

The button test is the universal ceramic industry method for evaluating feldspar quality before commercial purchase. A small sample of feldspar powder is pressed into a button shape and fired at a standard ceramic temperature (typically 1250°C). The fired button reveals the true melt quality, whiteness, surface smoothness, and flux performance of the feldspar.

Pink Potash Feldspar — Button Test Result

• Fired colour: cream to warm off-white — visible warm undertone from iron
• Melt: clean, uniform spread — K₂O vitrification is strong and consistent
• Surface: smooth, glassy — no pinholes, no crawling
• Assessment: excellent flux performance, acceptable colour for non-whiteness applications

White Potash Feldspar — Button Test Result

• Fired colour: snow white to bright white — high L* value, no warm undertone
• Melt: clean, uniform spread — K₂O vitrification is identical to pink grade
• Surface: smooth, glassy, pinhole-free — premium surface finish
• Assessment: maximum whiteness, maximum surface quality, ideal for all whiteness-critical applications
• https://www.feldsparindia.com/pink-potash-feldspar.htm
• https://www.feldsparindia.com/white-potassium-feldspar-powder.htm

Global Export Markets — Where We Supply Both Grades