Ask the Chatbot Games & Quizzes History & Society Science & Tech Biographies Animals & Nature Geography & Travel Arts & Culture ProCon Money Videos
Gypsum plaster
Introduction References & Edit History Related Topics
Images
Gypsum plaster bust of Julius Caesar showing a realistic, clean-shaven face with short hair, high cheekbones, and a solemn expression against a black background. Gypsum plaster dental model showing upper and lower teeth in occlusion, set against a black background.
Quick Facts
Related Topics:
Cement
gypsum
Plaster
See all related content
Britannica AI Icon
Adding us as a Preferred Source tells Google you trust our content, so our articles show up more often in your Google Search, Discover feed, and AI Overviews.
verifiedCite
While every effort has been made to follow citation style rules, there may be some discrepancies. Please refer to the appropriate style manual or other sources if you have any questions.
Select Citation Style
Feedback
Corrections? Updates? Omissions? Let us know if you have suggestions to improve this article (requires login).
Thank you for your feedback

Our editors will review what you’ve submitted and determine whether to revise the article.

External Websites
Gypsum plaster bust of Julius Caesar showing a realistic, clean-shaven face with short hair, high cheekbones, and a solemn expression against a black background.
Julius Caesar Bust of Julius Caesar made of gypsum plaster.

Gypsum plaster

building material
Written and fact-checked by
Britannica Editors
Encyclopaedia Britannica's editors oversee subject areas in which they have extensive knowledge, whether from years of experience gained by working on that content or via study for an advanced degree....
Britannica Editors
Last updated
•History

Gypsum plaster, white cementing material made by partial or complete dehydration of the mineral gypsum, commonly with special retarders or hardeners added. Applied in a plastic state (with water), it sets and hardens by chemical recombination of the gypsum with water.

For especially hard finish plaster, the gypsum is completely dehydrated at high temperature, and such chemicals as alkali sulfate, alum, or borax are added. Hair or fibre and lime or clay may be added to the plasters during manufacture. The plaster coats, except for some finish coats, are sanded. See also plaster of paris.

This article was most recently revised and updated by Amy Tikkanen.