Editing Soapstone (section)

==Physical characteristics==
Soapstone is relatively soft because of its high talc content—talc has a definitional value of 1 on the [[Mohs scale of mineral hardness|Mohs hardness scale]]. Softer grades may feel similar to [[soap]] when touched, hence the name. No fixed hardness is given for soapstone because the amount of talc it contains varies widely, from as little as 30% for architectural grades such as those used on countertops, to as much as 80% for carving grades.

Soapstone is easy to carve; it is also durable and heat-resistant and has a high heat storage capacity. It has therefore been used for cooking and heating equipment for thousands of years.<ref name=hansen>{{cite book| last1=Hansen|first1=Gitte|last2=Storemyr|first2=Per|title=A Versatile Resource – The Procurement and Use of Soapstone in Norway and The North Atlantic Region. In: Soapstone in the North Quarries, Products and People 7000 BC – AD 1700. UBAS – University of Bergen Archaeological Series 9. |year=2017 |place=Bergen, Norway |url=http://bora.uib.no/handle/1956/16580 |isbn=978-82-90273-90-8}}</ref>

Soapstone is often used as an [[Electrical insulation|insulator]] for housing and electrical components, due to its durability and electrical characteristics and because it can be pressed into complex shapes before firing. Soapstone undergoes transformations when heated to temperatures of {{convert|1000|–|1200|°C|°F}} into [[enstatite]] and [[cristobalite]]; on the Mohs scale, this corresponds to an increase in hardness to 5.5–6.5.<ref>"Some Important Aspects of the Harappan Technological Tradition," Bhan KK, Vidale M and Kenoyer JM, in ''Indian Archaeology in Retrospect''/edited by S. Settar and Ravi Korisettar, Manohar Press, New Delhi, 2002.</ref> The resulting material, harder than glass, is sometimes called "lava".<ref name=Hall>{{cite journal |last1=Hall |first1=A. L. |title=On the talc deposits near Kaapmuiden, in the Eastern Transvaal |journal=Transactions of the Geological Society of South Africa |date=1927 |volume=30 |page=83 |url=https://journals.co.za/doi/pdf/10.10520/AJA10120750_1652}}</ref>