| Title | स्लेट पत्थर (Slate)Rare Sleṭ patthar Slate |
|---|---|
| Description | स्लेट - Slet (Slate), known in Indic languages as *पट्टिका पत्थर* (paṭṭikā pathar – slab stone) or *शिलापट्ट* (shilāpaṭṭa – rock slab), is a fine-grained, foliated metamorphic rock extensively utilized in Indic heritage architecture, particularly in regions like Himachal Pradesh and Uttarakhand [1]. Formed from shale under low-grade metamorphism, its primary mineral composition includes quartz, muscovite, and chlorite. Density ranges from 2600-2800 kg/m³, with low water absorption (<0.3%) and flexural strength of 30-60 MPa. Traditional quarries in the Kullu Valley and Kangra Valley provided *श्यामपट शिला* (shyāmapaṭa shilā – blackboard stone) for roofing tiles and paving stones. The Katoch Dynasty and other local rulers employed slate extensively from the Medieval period onwards. Slate's low thermal expansion (8-10 x 10⁻⁶ /°C) and moderate thermal conductivity (2.5-3.0 W/mK) made it suitable for roofing in the Himalayan climate. Conservation efforts at heritage sites like those in Chamba Kingdom require careful matching of original *लेखन शिला* (lekhana shilā – writing stone) and traditional processing methods to maintain structural integrity and aesthetic value [2]. Restoration necessitates understanding slate's geological origin and potential weathering mechanisms [3]. |
| Also Known As | Slate Sleṭ patthar Slate Slate Stone Roofing Slate Writing Slate पट्टिका पत्थर शिलापट्ट श्यामपट शिला लेखन शिला स्लेट |
| Tags | शैलखटी Shailakhaṭī Slate Roofing Metamorphic स्लेट Kangra Chamba Stone Metamorphic Rock Slet |
| Material ID | INHFMAT-941539446-20-11-25-SA |
| URI | https://www.inheritage.foundation/aat/material/slate |
| API Endpoint | https://inheritage.foundation/api/v1/aat/materials/slate |
| Total Sites | 1 |
| Primary Sites | 0 |
| Created | November 20, 2025 |
| Last Updated | November 28, 2025 |
| Types | Metamorphic Rock Roofing Material Foliated Rock Building Stone |
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| Regions | Himachal Pradesh Uttarakhand Kullu Valley Kangra Valley Chamba |
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| Time Periods | Medieval Period Colonial Period 16th Century CE 17th Century CE 18th Century CE 19th Century CE 20th Century CE 10th-11th Century CE |
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| Dynasties | Katoch Dynasty Local Rulers Chamba Kingdom Kullu Kingdom Rajput Dynasty British Empire |
| Sources | Himalayan slate quarries Local slate quarries in Kangra Valley Local slate quarries in Himachal Pradesh Local slate quarries near Kinner Kailash Local slate quarries near Manali Local slate quarries near Chamba Local slate quarries in Kullu region |
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| Properties | Density: 2600-2800 kg/m³ Water absorption: <0.3% Flexural strength: 30-60 MPa Thermal expansion: Low Thermal conductivity: 2.5-3.0 W/mK Mineral composition: Quartz, Muscovite, Chlorite Thermal Expansion Coefficient: 8-10 x 10⁻⁶ /°C |
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| Uses | Roofing tiles Paving stones Wall cladding Flooring Blackboards |
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| Materials | Iron (for fasteners) Timber (for roof structure) Lime Mortar Wood |
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| Styles | Kath-Kuni architecture Colonial architecture Vernacular architecture Nagara architecture Himalayan architecture Pahari architecture Victorian architecture |
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| Categories | Residential buildings Government buildings Temple Residential Buildings Fort Roofing Palace House School Church |
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| Notes |
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| Title | Type | Notes |
|---|---|---|
| Geological Survey of India Reports | Geological Survey | Slate deposits in India |
| Building Materials Evaluation Reports | Technical Report | Slate properties and durability |
| Building Stones of India | Book | Slate properties |
| Geological Survey of India Reports | Technical Report | Slate deposits and properties |
| Building Materials Handbook | Textbook | Slate properties |
| Site Name | Status | Usage | Confidence |
|---|---|---|---|
| ISKCON Toronto Hare Krishna Temple | Secondary | Walls | 100% |