Aventurine

Object/Artifact

-

Crater Rock Museum

Name/Title

Aventurine

Entry/Object ID

2014.1.148

Description

Chemical Composition: SiO2 Crystal System: Hexagonal System Description: Common Name: Aventurine Chemistry: SiO2 Group: Carbonates Description: A trapazoidal shaped piece with mica inclusions which cast a silvery sheen to the light green Aventurine. PHYSICAL PROPERTIES ; Chemical Formula SiO2 Color Blue, Green, Yellow, Orange, Brown, Gray Hardness 6.5 - 7 Crystal System Hexagonal Refractive Index 1.54 - 1.55 SG 2.63 - 2.65 Transparency Opaque. May be translucent when backlit on the edges. Double Refraction .009 Luster Vitreous, waxy Cleavage Indiscernible Mineral Class Quartz / Chalcedony - See more at: http://www.minerals.net/gemstone/aventurine_gemstone.aspx#sthash.cSM3p7ie.dpuf Aventurine is a form of quartz, characterised by its translucency and the presence of platy mineral inclusions that give a shimmering or glistening effect termed aventurescence. Aventurine (unknown scale)The most common colour of aventurine is green, but it may also be orange, brown, yellow, blue, or gray. Chrome-bearing fuchsite (a variety of muscovite mica) is the classic inclusion, and gives a silvery green or blue sheen. Oranges and browns are attributed to hematite or goethite. Because aventurine is a rock, its physical properties vary: its specific gravity may lie between 2.64-2.69 and its hardness is somewhat lower than single-crystal quartz at around 6.5. Hardness: 7 Quartz Luster: Waxy Rock Origin: Post-depositional Rock Type: Igneous Specific Gravity: 2.6-2.8 Variety: Aventurine feldspar or sunstone can be confused with orange and red aventurine quartzite, although the former is generally of a higher transparency. Aventurine is often banded and an overabundance of fuchsite may render it opaque, in which case it may be mistaken for malachite at first glance. The name aventurine derives from the Italian "a ventura" meaning "by chance". This is an allusion to the lucky discovery of aventurine glass or goldstone at some point in the 18th century. Although it was known first, goldstone is now a common imitation of aventurine and sunstone. Goldstone is distinguished visually from the latter two minerals by its coarse flecks of copper, dispersed within the glass in an unnaturally uniform manner. It is usually a golden brown, but may also be found in blue or green. The majority of green and blue-green aventurine originates in India (particularly in the vicinity of Mysore and Madras) where it is employed by prolific artisans. Creamy white, gray and orange material is found in Chile, Spain and Russia. Most material is carved into beads and figurines with only the finer examples fashioned into cabochons, later being set into jewellery. Main markets for aventurine are landscape stone, building stone, aquaria, monuments, and jewellery.

Collection

RAGM Mineral Collection

Acquisition

Accession

2014.1

Source or Donor

Crater Rock Museum (unknown donors)

Acquisition Method

Gift

Dimensions

Width

1-1/2 in

Depth

1 in

Length

2-1/2 in

Location

Location

Shelf

CS-E-3

Room

Curation Storage

Building

Crater Rock Museum

Date

July 29, 2023

Location

Building

Storage

Category

Permanent

Moved By

Scott Longan

Date

October 29, 2009

Location

Cabinet

K-1 rear

Wall

North

Building

Storage (old gift shop upstairs)

Category

Permanent