2.55 ct HOWLITE – USA

Howlite
Finding Howlite is easy, but finding the patience to cut it is another story. It is a notoriously challenging material for the lapidary because it is both incredibly soft and frustratingly fragile. In my experience, most people treat it as a secondary material for carvings or cheap beads, but when you take the time to treat it with respect, the stark white porcelain-like finish and those jagged black “spider-web” veins create a minimalist aesthetic that is hard to beat. I’ve always found that the trick is managing the pressure; one wrong move and the stone simply crumbles under the weight of the lap.

The Heritage & Discovery

Historical Significance: Howlite is often the “chameleon” of the gem world. Because of its porous nature, it is frequently dyed blue to imitate turquoise or red to mimic coral. For a serious collector, however, the value is in its natural state. It represents a purity of form, prized for that opaque, bone-white luster that has served as a canvas for both nature’s veining and human artistry since its discovery.

Discovery: The mineral was first identified in 1868 by Henry How, a Canadian mineralogist, in Nova Scotia. He was alerted to it by miners in a gypsum quarry who found a “nuisance” mineral that was interfering with their work. He originally named it silico-boro-calcite, but it was later renamed in his honor.

Important Mines: The type locality in Brookville, Nova Scotia, remains historically significant, but the bulk of the world’s high-quality Howlite now emerges from the Tick Canyon deposit in California, USA. These deposits are famous for producing the large, cauliflower-like nodules that provide the best yield for those looking to attempt a clean cut.

Mineralogical Profile

Description: Howlite is a calcium borosilicate hydroxide that typically forms in evaporite deposits. It is an opaque, sub-vitreous mineral that sits at a delicate 3.5 on the Mohs scale. It lacks a distinct cleavage but is highly susceptible to “bruising” during the cutting process. Its most famous feature is the erratic, dark brown or black veins of matrix that provide a sharp contrast against its white-to-grey base color.

Chemical Formula: Ca₂B₅SiO₉(OH)₅