Zinc phosphate
A white inorganic compound used to protect metal and in dental cement
No single value: Zinc phosphate is a material, and its colour varies. The background shows its family, white.
Zinc phosphate is a white powder made from zinc, phosphorus, and oxygen. It is mainly used to shield metal from rust and as a dental cement for fixing crowns and bridges. This compound has replaced older, more hazardous corrosion inhibitors containing lead or chromium.
- Forms a white powder used to protect metal from rust
- Main ingredient in traditional dental cement
- Replaced lead and chromium compounds for corrosion protection
- Natural forms include hopeite and parahopeite minerals
What colour is Zinc phosphate?
Zinc phosphate is a chemical compound that appears as a white powder. It is valued for its ability to form a protective layer on metal, helping to prevent rust. Its use is not limited to industry; it also finds a place in dental work, where it serves as a cement for various restorations. In nature, related minerals such as hopeite and parahopeite occur in zinc ore deposits.
Where does Zinc phosphate come from?
The name comes from its chemical makeup, combining zinc and phosphate ions. While the compound itself is manufactured, similar minerals have been found in the oxidation zones of zinc ore beds, formed when sphalerite reacts with phosphate-rich water. The anhydrous form has not been discovered in nature.
How is Zinc phosphate made?
Zinc phosphate is produced by reacting zinc with phosphate sources, resulting in a white powder. To ensure an even coating on metal, a seeding agent like sodium pyrophosphate is often applied first. This helps the zinc phosphate layer form more effectively, especially on crystalline surfaces.
Where Zinc phosphate is used
This compound is mainly applied to metal as a protective layer to slow down corrosion. It is also a key ingredient in primer paints. In dentistry, zinc phosphate cement is used to fix crowns, bridges, and other restorations, and sometimes as a temporary filling. Its adoption has reduced the use of more dangerous lead- or chromium-based inhibitors.
White around the world
What the white family means from country to country.
The Taliban flag is white with the Muslim declaration of faith in black. It replaced the black, red and green tricolour of the republic in 2021.
Politics and protestSacred and holySource: Flag of AfghanistanThe Mothers of the Plaza de Mayo wore white headscarves as they marched to demand news of children who disappeared under the dictatorship of 1976 to 1983.
Politics and protestMourning and deathCourageSource: Mothers of Plaza de MayoThe wiphala, a square flag of 49 small squares in seven colours with a white diagonal, stands for the Andean peoples. It has been a second national flag since 2009.
Politics and protestPrideSource: WiphalaOn New Year's Eve crowds on the beaches dress in white for peace in the year ahead. The custom comes from the Afro-Brazilian religions, whose followers wear white.
Luck and prosperityFestival and celebrationSacred and holyHopeSource: New Year's EveAn ordinary citizen's kabney is white with fringes. It must be worn to enter a dzong, the fortress that houses both monks and government offices.
Purity and peaceSource: KabneyA red cross on white, the Swiss flag reversed, marks medical staff and aid workers in war and must not be attacked under the Geneva Conventions.
Protection and healingTrustSource: Emblems of the International Red Cross and Red Crescent MovementShades and relatives of Zinc phosphate
Natural forms of zinc phosphate include the minerals hopeite and parahopeite. Another related mineral is tarbuttite, which contains water in its structure. These minerals are found in areas where zinc ores have been exposed to phosphate-rich conditions.
Questions people ask about Zinc phosphate
What colour is zinc phosphate?
Zinc phosphate is a white powder, both in its industrial form and as found in related minerals.
Where does the name zinc phosphate come from?
The name reflects its chemical composition, which combines zinc and phosphate ions.
What is zinc phosphate used for?
It is mainly used to protect metal from rust and as a cement in dental procedures for fixing crowns and bridges.
Is zinc phosphate found in nature?
While the manufactured compound is common, similar minerals like hopeite and parahopeite occur naturally in zinc ore deposits.
Why is zinc phosphate preferred over older corrosion inhibitors?
It has replaced more toxic lead- and chromium-based compounds, making it a safer choice for protecting metal.
Good reading and sources
The facts on this page come from the Wikipedia article "Zinc phosphate", written by its contributors and used under the CC BY-SA 4.0 licence, and from its Wikidata record (CC0). Rang rewrote the text in its own words, with AI assistance, and compares every page with the article to make sure no passage is copied. It may be reused under the same CC BY-SA 4.0 licence with a link back.
It may contain mistakes. The swatch is an approximation: named colours are not fixed standards, and every screen shows them a little differently. If something is wrong, tell us. Last refreshed 2026-10-03.
More of the white family
All of white
#FFFFFF
White
The lightest colour, seen in snow, milk and chalk, and opposite to blackBasic colour
White
Zinc oxide
A white inorganic powder used in pigments, ointments, ceramics and electronicsPigment 路 馃嚠馃嚦 India +2
#FDF8FF
Zinc white
A cool, low-toxicity white pigment made from zinc oxidePigment
#FFFEEF
Titanium white
A bright white pigment made from titanium dioxide, valued for its strong coveragePigment 路 馃嚭馃嚫 United States +1
White
Lead white
A dense, opaque white pigment once used in art, home, and cosmetics worldwidePigment 路 馃嚚馃嚦 China +2
White
Titanium dioxide
A brilliant white pigment made from titanium, used in paints, food and sunscreenPigment 路 馃嚚馃嚦 China +5
White
Barium sulfate
A dense, white mineral used in pigments, X-rays, and industryPigment
White
Antimony trioxide
A white antimony compound used in flame retardants and glassmakingPigment 路 馃嚚馃嚦 China +4