Crystals & Minerals

Iceland Spar, also known as optical calcite, is a clear, transparent variety of calcite famous for its unique optical property called double refraction. When you place the crystal over text or an image, it appears doubled — a visual effect that occurs because light splits into two rays as it passes through the crystal. This fascinating trait made Iceland spar historically important in early optical instruments and scientific studies, including navigation and the development of polarizing microscopes.

It’s typically colorless or very lightly tinted and forms naturally in sharp, rhombohedral shapes. High-quality Iceland spar is most famously found in Iceland, though it also occurs in places like Mexico, the U.S., and China.

Iceland Spar (optical calcite) is often associated with clarity, insight, and truth. Because of its double refraction property, some see it as a symbol of seeing beyond surface appearances — helping to highlight different perspectives or reveal hidden aspects of a situation. It's thought to support clear thinking and honest communication, making it a favorite for meditation or decision-making spaces.

Name: Iceland Spar Optical Calcite
Specimen Size:  Miniature-Sized
Dimensions: 30x27x25 mm / 1.2x1.1x1.0 inches 
Weight: 44 Grams / 1.5 Ounces
Origin: Guangxi Province, China

This is a specimen of Strontianite and calcite crystals on matrix from Mandata, Pennsylvania.  Strontianite is a rare mineral made mostly of strontium carbonate and is an important source of the metal strontium. It usually forms in hydrothermal veins and limestone deposits, often found alongside minerals like calcite and fluorite. Strontianite can appear in different colors, including white, gray, yellow, green, or brown, and has a glassy or slightly shiny look. It was first discovered in Strontian, Scotland, which is how it got its name, and it can also be found in Germany, Italy, China, and parts of the United States. This mineral is mainly used to extract strontium, which is important for making red fireworks, ceramics, and special types of glass.

The top of the specimen is an exposed vug containing four sharp strontianite crystals sitting on a bed of small transparent calcite crystals. The strontianite fluoresces strongly white under long wave UV.  The specimen is in excellent condition.

Name: Strontianite on Calcite Crystals 
Specimen Size:   Cabinet-Sized
Dimensions: 82x69x43 mm / 3.2x2.7x1.7 inches
Weight: 215 gr / 7.6 Ounces 
Origin:  Mandata, Pennsylvania, USA

This is an attractive specimen of calcite crystals from the Wessels Mine, Kuruman, South Africa.  The entire top surface of the specimen is covered with many sharp well formed calcite crystals. Some are a frosted snow white ball shape which sit amongst a sharper sparkly druzy calcite. It is in excellent condition.

Calcite is found throughout the world in sedimentary, metamorphic, and igneous rocks. Some geologists consider it to be a "ubiquitous mineral" - one that is found everywhere. Calcite is the principal constituent of limestone and marble.

Name: Calcite Crystal
Specimen Size:  Cabinet-Sized
Dimensions:  61x50x35 mm/ 2.4x2.0x1.4 inches 
Weight: 96.82 Grams / 3.4 Ounces 
Origin: Mined in Wessels Mine, Kuruman, South Africa 

Iceland spar, formerly called Iceland crystal (Icelandic: silfurberg [ˈsɪlvʏrˌpɛrk], lit. 'silver-rock') and also called optical calcite, is a transparent variety of calcite, or crystallized calcium carbonate, originally brought from Iceland, and used in demonstrating the polarization of light.  

The most common crystal structure of Iceland spar is rhombohedral, but other structures, such as scalenohedral or prismatic, can form depending on formation conditions. Iceland spar is primarily found in Iceland but can occur in different parts of the world with suitable geological conditions such as China.

Name: Iceland Spar Optical Calcite
Specimen Size:  Miniature-Sized
Dimensions: 30x27x25 mm / 1.2x1.1x1.0 inches 
Weight: 60.8 Grams / 2.1 Ounces
Origin: Guangxi Province, China

This is a natural cluster formation of large calcite crystals with hematite inclusions. This piece has some white color to translucent crystals with areas of orange/red coloring from hematite inclusions, with sharp tabular crystal formations. There are some nicks and imperfections on a few crystals but would still shine in the proper setup.  They don't take away from how interesting this piece is.  Would be a nice addition to any new or existing collection.

Name: Calcite with Hematite Crystal Cluster
Specimen Size:  Cabinet-Sized
Dimensions: 95x81x45 mm / 3.7x3.2x1.8 inches 
Weight: 267.8 Grams / 9.4 oz 
Origin: Mined in Lane Quarry, Westfield, Hampden Co., Massachusetts, USA

This is a natural cluster formation of calcite on calcite crystals or two variations of the mineral found in a cracked concretion in a coal mine in Oskaloosa, Mahaska County, Iowa, USA.

It is a specimen consisting of two types of calcite on matrix. The first type is a coating of iridescent, dark calcite on the matrix. The second type are white crystals of calcite.   It is in good condition.  Would be a nice addition to any new or existing collection.

Name: Calcite on Calcite Crystal Cluster
Specimen Size:  Cabinet-Sized
Dimensions:  65x47x32 mm / 2.6x1.8x1.3 inches
Weight: 64 Grams / 2.2 oz 
Origin: Mined in Oskaloosa, Mahaska County, Iowa, USA

This is a beautiful combination of Calcite and Stilbite on Apophyllite crystal cluster.

Calcite is found throughout the world in sedimentary, metamorphic, and igneous rocks. Some geologists consider it to be a "ubiquitous mineral" - one that is found everywhere. Calcite is the principal constituent of limestone and marble. Stilbite is perhaps the most popular zeolite mineral for collectors. Stilbite is a handsome specimen with its pearly luster and sometimes colorful pink tints.  Apophyllite is transparent to translucent and is commonly found in colorless or white varieties, although it can also occur in shades of green, pink, yellow, or brown.

This nice crystal specimen would be a beautiful addition to any new or existing collection.

Name: Calcite, Stilbite and Apophyllite cluster 
Specimen Size:  Cabinet-Sized
Dimensions:  62x59x46 mm / 2.4x2.3x1.8 inches
Weight: 185 grams / 6.5 ounces 
Origin: Mined in Jalgaon, India

This is a natural cluster formation of large calcite crystals with hematite inclusions. This piece has some white color to translucent crystals with areas of orange/red coloring from hematite inclusions, with sharp tabular crystal formations. There are some nicks and imperfections on a few crystals but would still shine in the proper setup.  They don't take away from how interesting this piece is.  Would be a nice addition to any new or existing collection.

Name: Calcite with Hematite Crystal Cluster
Specimen Size:  Miniature-Sized
Dimensions: 56x51x29 mm / 2.2x2.0x1.1 inches 
Weight: 58 Grams / 2.0 oz 
Origin: Mined in Lane Quarry, Westfield, Hampden Co., Massachusetts, USA

Sharp terminated metallic crystals of tetrahedrite with quartz crystals and covered with rare siderite and sphalerite. The sphalerite on the cluster reacts to UV light with a lovely orange color.  This top specimen is in very good condition. Would be a beautiful addition to any new or existing collection.

Name: Tetrahedrite, Sphalerite, Calcite and Siderite Crystal Cluster
Specimen Size:   Cabinet-sized
Dimensions:  88x76x63 mm / 3.5x3x2.5 inches
Weight: 670 Grams /  1Lb 7 oz
Origin: Mined in Huaron Mine, Peru

This is a natural cluster formation of large calcite crystals with hematite inclusions. This piece has some white color to translucent crystals with areas of orange/red coloring from hematite inclusions, with sharp tabular crystal formations. There are some nicks and imperfections on a few crystals but would still shine in the proper setup.  Those don't take away from how interesting this piece is.  Would be a nice addition to any new or existing collection.

Name: Calcite with Hematite Crystal Cluster
Specimen Size:  Miniature-Sized
Dimensions: 45x47x49 mm / 1.8x1.8x1.9 inches
Weight:  66.8 Grams / 2.3 oz
Origin: Mined in Lane Quarry Westfield, Hampden Co., Massachusetts, USA

The colorful apatite crystals are visible throughout this calcite vein with multiple small crystal being terminated. It has a nice luster and lovely colored hues with apatite in green, greenish blue and rare grey white. Would be a beautiful addition to any new or existing collection.

Name: Calcite vein with green, greenish blue and rare grey white Apatite crystal
Specimen Size:  Large Cabinet-Sized
Dimensions: 110x73x79 mm / 4.3x2.9x3.1 inches
Weight:  662 Gr / 1 lbs 7 oz
Origin: Eastern Ontario, Canada