Satin Spar
Satin spar is one of the three forms of pure natural crystalline gypsum, with one other, selenite, having a very similar features, the other natural form is gypsum rock which is commonly crushed and used in the manufacture of plaster products.
In old English gypsum was referred to as spear stone (spærstn) because of its crystal spear-like projections, of which selenite and satin spar have the most notable. Satin spar crystals are much more common than selenite crystals and often confused, whilst gypsum rock is relatively common. Other forms of crystalline gypsum are known as tabular gypsum, which is normally shorter blocks of satin spar, whilst desert roses form with grains of sand and gypsum flower which are referred to as crystal habits.
Satin Spar crystals are fibrous and white, and often appear as raw rulers or wands which can be polished into palmstones or spheres. They are translucent sideways but have quite clear light transmitting qualities lengthways, similar to fibre optics, when polished at the ends. Satin Spar crystals are sometime referred to a TV rock, because of these properties, although a mineral called Ulexite might also be referred to under the same name because it has similar qualities.
Selenite crystals on the other hand form in large flat, transparent crystals, often called plates or windows, sometimes called Lapis Specularis, and were used by the Romans in the construction of specularia (sometimes referred to as specularium), including the first types of windows before the development of glass for use in panes.
[edit] Related articles on Designing Buildings
- Botanical gardens
- Construction materials.
- Conservatory.
- Drywall construction.
- Garden greenhouse.
- Gypsum.
- Hydroponics and buildings.
- Lime plaster.
- Minerals of local and national importance.
- Mortar.
- Permission for mining or working of minerals.
- Plaster.
- Specularium.
- The secret life of the Georgian garden.
- Types of glass.
- Winter gardens.
Featured articles and news
Top 50 firms awarded 52bn of projects in the last year
New engineering data shows.
Enhancing construction site reporting efficiency
Through digitisation and the digital revolution.
Noise in the built environment
BSRIA guide TG 20/2021.
17,000 people suffer conditions as a result of exposure to excessive noise at work.
Turning down the noise: Auditory health
A pervasive risk with far-reaching consequences.
UK Construction Week, London is here !
Debuting major international pavilions and much more.
Getting the most out of heat pumps and heating
How heat pumps work and how they work best.
Plumbing and heating for successful retrofit and renovation
Low temperature underfloor systems and heat pumps.
Cost-of-living crisis and home improvement plans
Starting on the right footing and top tips for projects.
Delays on construction projects
Types, mitigation and the acceleration of works.
From Chaucer to Fawlty Towers.
Electrotechnical excellence, now open for entries.
Net zero electricity grids BSRIA guide NZG 5/2024
Outlining the changes needed to transition to net zero.
CIOB Global Student Challenge 2024
Universitas Indonesia wins for second year running.
ECA 2024 Apprentice of the Year Award
Entries open for submission until May 31.