Geological Information

Geological Information of Zeolites

• Generic name for a group of crystals often found together on the matrix
• About 40 natural zeolites have been identified during the past 200 years. It includes the following which are commonly found growing together in Indian deposits (along with fluorite,and chalcedony):
  • Common: Apophyllite, Heulandite, Prehnite, Cavansite, Okenite, Scolecite, Calcite, Pectolite, Gyrolite and Stilbite.
  • Uncommon: analcime, chabazite, clinoptilolite, pollute, erionite, ferrierite, laumontite, mordenite, mesolite, thomsonite, natrolite, and phillipsite.
• Natural zeolites form where volcanic rocks and ash layers react with alkaline groundwater.
• Commonly used as:
  • commercial adsorbents,water purification, as catalysts,
  • in nuclear reprocessing and production of laundry detergents.
  • in medicine and in agriculture.
  • heaps more uses for zeolites: read here.
• Much of it comes from Nasik, India.
  • Many have become rare as one of the two major mines was closed by the Government.
• Most if not all zeolites a soft and easy to break or scratch.

More about Some of the Members

Green Pectolite

• Usually green balls

Heulandite

• Comes in rhombic and coffin-shaped forms.
• More geological information.

Natrolite

• Mine has been closed.
• Seen only as minor inclusions on other zeolites and in Nunderite

Stilbite

• A low-temperature secondary hydrothermal mineral abundant in the volcanic rocks. Crystals are typically thin tabular.More information in Wikipedia.
• Crystal System: Monoclinic
• Mineral Class: Silicates
• Hardness: (3.5 - 4)

Okenite

• Small white cotton balls.
• Crystal System: Triclinic
• Mineral Class:Silicates 
• Hardness: (4-5) Color: white to slightly yellow, blue
• Easily damaged if touched.
• Mostly found in India. Read more in Wikipedia.

Mesolite

• a sodium calcium zeolite, is intermediate between natrolite, a sodium zeolite, and scolecite, a calcium zeolite:
  • http://www.galleries.com/Mesolite and
  • https://www.metaphysicalrealm1.com/mesolite1.html.
• Specialists may be able differentiate between scolecite, nautrolite and mesolite but most of us can't.

Apophyllite

• Apophyllite forms a flat-topped pyramid point or if the top has been knocked off then cubes
• Type: Mineral
• Class: Silicates
• Member of Group: Zeolites
• Mohs Hardness: 4.5 - 5
• Formula: (K,Na)Ca₄Si₈O₂₀(F,OH)·8H₂O
• Crystal System: Tetragonal
• Crystal Habit: Prism, tabular, massive
• Lustre / Diaphaneity: Transparent to translucent, Vitreous; pearly
• Colour: Usually white, colorless; also blue, green, brown, yellow, pink, violet
• Read more geological information.

Special Notes

• Many people mistake it for clear quartz - however this unique crystal shape will tell you its not.
• Apophyllite has become harder to get (and this more expensive) after one major -mine (of two) was shut down by Indian Government for safety reasons.
• Though relatively unfamiliar to the general public, apophyllite is fairly prevalent around the world but little comes onto the market.

Stilbite:

• A low-temperature secondary hydrothermal mineral abundant in the volcanic rocks.
• Crystals are typically thin tabular.
• More information in Wikipedia.
• Crystal System: Monoclinic
• Mineral Class: Silicates
• Group: Zeolites
• Hardness: (3.5 - 4)
• Colour: Colorless or white, also yellow, brown, pink, salmon, orange, red, green, blue or black.