Most lapis lazuli also contains calcite (white), sodalite (blue), and pyrite (metallic yellow). It is sometimes mistaken for sodalite and has been used as imitation lapis lazuli. Nepheline is very abundant and there is also cancrinite, sodalite, scapolite, calcite, biotite and hornblende. It is essentially a microcline, sodalite and cancrinite variety of nepheline syenite. It may also be substituted by spinel or sodalite, or by dyed jasper or howlite. Ultramarine is the aluminosilicate zeolite with a sodalite structure. Of these the former consists of orthoclase, nepheline, sodalite, diopside and aegirine, biotite and sphene. In nature it is frequently altered to zeolites (especially natrolite), sodalite, kaolin, or compact muscovite. Although massive sodalite samples are opaque, crystals are usually transparent to translucent. It consists of sodalite cages which are connected through hexagonal prisms. Much sodalite will also fluoresce a patchy orange under UV light. Most sodalite will fluoresce orange under ultraviolet light, and hackmanite exhibits tenebrescence. Eventually, sodalite is found along hydrothermal fractures. A significant deposit of the semi-precious mineral sodalite is located near Mont-Saint-Hilaire. The stone is long, and made of Brazilian sodalite.