CAVANSITE STILBITE Specimen Blue Crystal Cluster Mineral INDIA w/ ID card For Sale

This listing is for a really fascinating cavansite specimen in a display jar,
including an info card about this mineral and the location this specimen came from.
This kit is great for avid mineral specimen collectors or beginners.
It would be a perfect gift set for getting someone interested in mineral collecting and science.
The 1 centimeter scale cube is for size comparison only. It is not included in the sale.
The photos are of several different specimens, but this listings is for one specimen with an info card.
The photos show multiple specimens to give a representation of the variety of shapes and colors in these specimens.I offer a shipping discount for customers who combine their payments for multiple purchases into one payment!
The discount is regular shipping price for the first item and just 50 cents for each additional item!
To be sure you get your shipping discount just make sure all the items you want to purchase are in your cart.
sales you win are added to your cart automatically.
For any \"buy it now\" items or second chance offers, be sure to click the \"add to cart\" button, NOT the \"buy it now\" button.
Onceall of your items are in your cart just pay for them from your cart andthe combined shipping discount should be applied automatically.I offer a money back guarantee on every item I sell.
If you are not 100% happy with your purchase just send me a message to let me know
and I will buy back the item for your full purchase price.Hi there. I am selling this really lovely cavansite mineral specimen. It is from Poona, India. If you have any questions, do not hesitate to ask me. Have fun offerding, thanks so much for visiting my sale and have a great day!

The following is a wikipedia entry about cavansite:

General

Category Silicate mineral

Formula

(repeating unit) Ca(VO)Si4O10·4(H2O)

IMA symbol Cav[1]

Crystal system Orthorhombic

Crystal class Dipyramidal (mmm)

H–M Symbol: (2/m 2/m 2/m)

Space group Pcmn

Unit cell a = 9.792(2) Å,

b = 13.644(3) Å,

c = 9.629(2) Å; Z = 4

Identification

Color Brilliant sky-blue to greenish blue

Crystal habit Radiating acicular prismatic crystals commonly as spherulitic rosettes

Cleavage Good on {010}

Tenacity Brittle

Mohs scale hardness 3 - 4

Luster Vitreous, pearly

Streak Bluish-white

Diaphaneity Transparent

Specific gravity 2.25 - 2.33

Optical properties Biaxial (+)

Refractive index nα = 1.542(2) nβ = 1.544(2) nγ = 1.551(2)

Birefringence δ = 0.009

Pleochroism Visible: X=Z= colorless Y= blue

2V angle Measured: 52°

References [2][3][4][5]

Cavansite, whose name is derived from its chemical composition, calcium vanadium silicate, is a deep blue hydrous calcium vanadium phyllosilicate mineral, occurring as a secondary mineral in basaltic and andesitic rocks along with a variety of zeolite minerals. It\'s blue coloring comes from vanadium, a metal ion.[6] Discovered in 1967 in Malheur County, Oregon, cavansite is a relatively rare mineral. It is polymorphic with the even rarer mineral, pentagonite. It is most frequently found in Pune, India and in the Deccan Traps, a large igneous province.

Uses of cavansite

Although cavansite contains vanadium, and could thus be a possible ore source for the element, it is not generally considered an ore mineral. However, because of its rich color and relative rarity, cavansite is a sought-after collector\'s mineral.

Associated minerals

Members of the apophyllite group

Members of the zeolite group, particularly stilbite

babingtonite, Ca2Fe2Si5O14OH

quartz, SiO2

calcite, CaCO3

pentagonite, Ca(VO)Si4O10 · 4(H2O)

Notes for identification

Cavansite is a distinctive mineral. It tends to form crystal aggregates, generally in the form of balls, up to a couple centimeters in size. Sometimes the balls are coarse enough to allow the individual crystals to be seen. Rarely, cavansite forms bowtie-shaped aggregates. The color of cavansite is distinctive, almost always a rich, bright blue. The color is the same as its dimorph, pentagonite, but the latter is generally much more spikey with bladed crystals. Finally, the associated minerals are useful for identification, as cavansite is frequently found sitting atop a matrix of zeolites or apophyllites.